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Search: a288834 -id:a288834
Displaying 1-7 of 7 results found. page 1
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A066373 a(n) = (3*n-2)*2^(n-3). +10
7
2, 7, 20, 52, 128, 304, 704, 1600, 3584, 7936, 17408, 37888, 81920, 176128, 376832, 802816, 1703936, 3604480, 7602176, 15990784, 33554432, 70254592, 146800640, 306184192, 637534208, 1325400064, 2751463424, 5704253440 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,1
COMMENTS
An elephant sequence, see A175654. For the corner squares 16 A[5] vectors, with decimal values between 59 and 440, lead to this sequence (with a leading 1 added). For the central square these vectors lead to the companion sequence A098156 (without a(1)). - Johannes W. Meijer, Aug 15 2010
a(n) is the total number of 1's in runs of 1's of length >= 2 over all binary words with n bits. - Félix Balado, Jan 15 2024
LINKS
M. Azaola and F. Santos, The number of triangulations of the cyclic polytope C(n,n-4), Discrete Comput. Geom., 27 (2002), 29-48.
FORMULA
G.f.: x^2*(2-x)/(1-2x)^2. - Emeric Deutsch, Jul 23 2006
a(n) = 2*a(n-1) +3*2^(n-3). - Vincenzo Librandi, Mar 20 2011
a(n+1) - a(n) = A098156(n). - R. J. Mathar, Apr 25 2013
From Paul Curtz, Jun 29 2018: (Start)
a(n) = A130129(n-2) - A130129(n-3) for n >= 2.
Binomial transform of A016789.
Inverse binomial transform of A288834.
Also the main diagonal of the difference table of m -> (-1)^m*(m+2).
2, -3, 4, -5, ...
-5, 7, -9, 11, ...
12, -16, 20, -24, ...
-28, 36, -44, 52, ... . (End)
MAPLE
seq((3*n-2)*2^(n-3), n=2..30); # Emeric Deutsch, Jul 23 2006
MATHEMATICA
Array[(3 # - 2)*2^(# - 3) &, 28, 2] (* or *)
Drop[CoefficientList[Series[x^2*(2 - x)/(1 - 2 x)^2, {x, 0, 29}], x], 2] (* Michael De Vlieger, Jun 30 2018 *)
PROG
(PARI) { for (n=2, 200, write("b066373.txt", n, " ", (3*n - 2)*2^(n - 3)) ) } /* Harry J. Smith, Feb 11 2010 */
CROSSREFS
Column k=2 of A229079.
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 04 2002
STATUS
approved
A080420 a(n) = (n+1)*(n+6)*3^n/6. +10
7
1, 7, 36, 162, 675, 2673, 10206, 37908, 137781, 492075, 1732104, 6022998, 20726199, 70681653, 239148450, 803538792, 2683245609, 8910671247, 29443957164, 96855122250, 317297380491, 1035574967097, 3368233731366, 10920608743932, 35303692060125, 113819103201843 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
Gregory Gerard Wojnar, Daniel Sz. Wojnar, and Leon Q. Brin, Universal peculiar linear mean relationships in all polynomials, arXiv:1706.08381 [math.GM], 2017. See p. 4.
FORMULA
G.f.: (1-2*x)/(1-3*x)^3.
From G. C. Greubel, Dec 22 2023: (Start)
a(n) = (n+6)*A288834(n)/2, for n >= 1.
a(n) = A136158(n+2, 2).
E.g.f.: (1/2)*(2 + 8*x + 3*x^2)*exp(3*x). (End)
From Amiram Eldar, Jan 11 2024: (Start)
Sum_{n>=0} 1/a(n) = 17721/50 - 4356*log(3/2)/5.
Sum_{n>=0} (-1)^n/a(n) = 4392*log(4/3)/5 - 12591/50. (End)
MATHEMATICA
CoefficientList[Series[(1 - 2 x) / (1 - 3 x)^3, {x, 0, 30}], x] (* Vincenzo Librandi, Aug 05 2013 *)
Table[(n+1)(n+6)3^n/6, {n, 0, 30}] (* or *) LinearRecurrence[{9, -27, 27}, {1, 7, 36}, 30] (* Harvey P. Dale, Apr 02 2019 *)
PROG
(Magma) [(n+1)*(n+6)*3^n/6: n in [0..30]]; // Vincenzo Librandi, Aug 05 2013
(SageMath) [(n+1)*(n+6)*3^n/6 for n in range(31)] # G. C. Greubel, Dec 22 2023
CROSSREFS
T(n,2) in triangle A080419.
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Feb 19 2003
STATUS
approved
A288836 a(n) = (1/3!)*3^(n+1)*(n+5)*(n+1)*(n). +10
4
18, 189, 1296, 7290, 36450, 168399, 734832, 3070548, 12400290, 48715425, 187067232, 704690766, 2611501074, 9542023155, 34437376800, 122941435176, 434685788658, 1523724783237, 5299912289520, 18305618105250, 62824881337218, 214364018189079, 727538485975056 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
O.g.f.: z*3^2*(2-3*z)/(1-3*z)^4.
a(n) = -A287768(n+5,6).
CROSSREFS
Column k=6 of A287768.
KEYWORD
nonn
AUTHOR
STATUS
approved
A288835 a(n) = (1/2!)*3^n*(n+3)*(n). +10
3
6, 45, 243, 1134, 4860, 19683, 76545, 288684, 1062882, 3838185, 13640319, 47829690, 165809592, 569173311, 1937102445, 6543101592, 21953827710, 73222472421, 242912646603, 801960412230, 2636009007156, 8629791392475, 28148810469273, 91507169819844 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
O.g.f.: z*3^1*(2-3*z)/(1-3*z)^3.
a(n) = A287768(n+3,4).
MATHEMATICA
Table[(1/2!)*3^n*(n + 3) n, {n, 24}] (* Michael De Vlieger, Jun 23 2017 *)
LinearRecurrence[{9, -27, 27}, {6, 45, 243}, 30] (* Harvey P. Dale, Apr 04 2020 *)
CROSSREFS
Column k=4 of A287768.
KEYWORD
nonn
AUTHOR
STATUS
approved
A288838 a(n) = (1/4!)*3^(n+2)*(n+7)*(n+2)*(n+1)*(n). +10
3
54, 729, 6075, 40095, 229635, 1194102, 5786802, 26572050, 116917020, 496897335, 2051893701, 8269753401, 32643763425, 126557359740, 482984209620, 1817776934388, 6757388169138, 24843338857125, 90429753439935, 326206114635555, 1167092987918319, 4144371018322194 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
O.g.f.: z*3^3*(2-3*z)/(1-3*z)^5.
a(n) = A287768(n+7,9).
MATHEMATICA
Table[1/4! 3^(n+2) (n+7)(n+2)(n+1)n, {n, 30}] (* or *) LinearRecurrence[{15, -90, 270, -405, 243}, {54, 729, 6075, 40095, 229635}, 30] (* Harvey P. Dale, May 15 2022 *)
PROG
(PARI) a(n)=3^n*3*n*(n+1)*(n+2)*(n+7)/8 \\ Charles R Greathouse IV, Jun 19 2017
CROSSREFS
Column k=9 of A287768.
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
A354314 Expansion of e.g.f. 1/(1 - x/3 * (exp(3 * x) - 1)). +10
2
1, 0, 2, 9, 60, 495, 4986, 58401, 780984, 11749779, 196446870, 3612882933, 72484364052, 1575418827879, 36875093680530, 924769734574185, 24737895033896304, 703105981990977915, 21159355356941587470, 672148402091190649629, 22475238194908656800460 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
a(0) = 1; a(n) = Sum_{k=2..n} k * 3^(k-2) * binomial(n,k) * a(n-k).
a(n) = n! * Sum_{k=0..floor(n/2)} 3^(n-2*k) * k! * Stirling2(n-k,k)/(n-k)!.
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1-x/3*(exp(3*x)-1))))
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=2, i, j*3^(j-2)*binomial(i, j)*v[i-j+1])); v;
(PARI) a(n) = n!*sum(k=0, n\2, 3^(n-2*k)*k!*stirling(n-k, k, 2)/(n-k)!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 23 2022
STATUS
approved
A288842 Triangle (sans apex) of coefficients of terms of the form (eM_1)^j*(eM_2)^k re construction of triangle A287768. +10
0
1, 2, 3, 9, 6, 9, 36, 45, 18, 27, 135, 243, 189, 54, 81, 486, 1134, 1296, 729, 162, 243, 1701, 4860, 7290, 6075, 2673, 486, 729, 5832, 19683, 36450, 40095, 26244, 9477, 1458, 2187, 19683, 76545, 168399, 229635, 199017, 107163, 32805, 4374, 6561, 65610, 288684, 734832, 1194102, 1285956, 918540, 419904, 111537, 13122 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
G. G. Wojnar, D. Sz. Wojnar, and L. Q. Brin, Universal Peculiar Linear Mean Relationships in All Polynomials, Table GW.n=3, p.22, arXiv:1706.08381 [math.GM], 2017.
FORMULA
T(n+1,k+1) = 3*T(n,k) + 3*T(n,k+1).
EXAMPLE
Triangle begins:
1, 2;
3, 9, 6;
9, 36, 45, 18;
MATHEMATICA
T[1, 1] = 1; T[1, 2] = 2;
T[n_, k_] /; 1 <= k <= n+1 := T[n, k] = 3 T[n-1, k-1] + 3 T[n-1, k];
T[_, _] = 0;
Table[T[n, k], {n, 1, 9}, {k, 1, n+1}] // Flatten (* Jean-François Alcover, Nov 16 2018 *)
CROSSREFS
Columns are: A000244, A288834, A288835, A288836, A288838, etc.
Cf. A287768.
KEYWORD
nonn,tabf
AUTHOR
STATUS
approved
page 1

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Last modified August 30 00:57 EDT 2024. Contains 375520 sequences. (Running on oeis4.)