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Egyptian fraction representation of sqrt(53) (A010506) using a greedy function.
+20
0
7, 4, 34, 1433, 3473810, 16229351336487, 949514635841230182654078450, 2889844410885034994651072554166092838631734010754362047, 90303610423494587890114446343335205731154007285533876023746429382538260256932049359769872513411427600496627202
OFFSET
0,1
MATHEMATICA
Egyptian[nbr_] := Block[{lst = {IntegerPart[nbr]}, cons = N[ FractionalPart[ nbr], 2^20], denom, iter = 8}, While[ iter > 0, denom = Ceiling[ 1/cons]; AppendTo[ lst, denom]; cons -= 1/denom; iter--]; lst]; Egyptian[ Sqrt[ 53]]
CROSSREFS
Egyptian fraction representations of the square roots: A006487, A224231, A248235-A248322.
Egyptian fraction representations of the cube roots: A129702, A132480-A132574.
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Oct 04 2014
STATUS
approved
Numerators of continued fraction convergents to sqrt(53).
+10
11
7, 22, 29, 51, 182, 2599, 7979, 10578, 18557, 66249, 946043, 2904378, 3850421, 6754799, 24114818, 344362251, 1057201571, 1401563822, 2458765393, 8777860001, 125348805407, 384824276222, 510173081629, 894997357851, 3195165155182, 45627309530399
OFFSET
0,1
COMMENTS
The terms of this sequence can be constructed with the terms of sequence A086902. For the terms of the periodical sequence of the continued fraction for sqrt(53) see A010139. We observe that its period is five. The decimal expansion of sqrt(53) is A010506. - Johannes W. Meijer, Jun 12 2010
LINKS
FORMULA
a(5*n) = A086902(3*n+1), a(5*n+1) = (A086902(3*n+2)-A086902(3*n+1))/2, a(5*n+2) = (A086902(3*n+2)+A086902(3*n+1))/2, a(5*n+3) = A086902(3*n+2) and a(5*n+4) = A086902(3*n+3)/2. - Johannes W. Meijer, Jun 12 2010
G.f.: -(x^9-7*x^8+22*x^7-29*x^6+51*x^5+182*x^4+51*x^3+29*x^2+22*x+7) / (x^10+364*x^5-1). - Colin Barker, Sep 26 2013
MATHEMATICA
Numerator[Convergents[Sqrt[53], 30]] (* Harvey P. Dale, Sep 24 2013 *)
CoefficientList[Series[-(x^9 - 7 x^8 + 22 x^7 - 29 x^6 + 51 x^5 + 182 x^4 + 51 x^3 + 29 x^2 + 22 x + 7)/(x^10 + 364 x^5 - 1), {x, 0, 40}], x] (* Vincenzo Librandi, Sep 27 2013 *)
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Sep 26 2013
STATUS
approved
Denominators of continued fraction convergents to sqrt(53).
+10
11
1, 3, 4, 7, 25, 357, 1096, 1453, 2549, 9100, 129949, 398947, 528896, 927843, 3312425, 47301793, 145217804, 192519597, 337737401, 1205731800, 17217982601, 52859679603, 70077662204, 122937341807, 438889687625, 6267392968557, 19241068593296, 25508461561853
OFFSET
0,2
COMMENTS
The terms of this sequence can be constructed with the terms of sequence A054413. For the terms of the periodic sequence of the continued fraction for sqrt(53) see A010139. We observe that its period is five. The decimal expansion of sqrt(53) is A010506. - Johannes W. Meijer, Jun 12 2010
LINKS
FORMULA
a(5*n) = A054413(3*n), a(5*n+1) = (A054413(3*n+1) - A054413(3*n))/2, a(5*n+2)= (A054413(3*n+1) + A054413(3*n))/2, a(5*n+3) = A054413(3*n+1) and a(5*n+4) = A054413(3*n+2)/2. - Johannes W. Meijer, Jun 12 2010
G.f.: -(x^8-3*x^7+4*x^6-7*x^5+25*x^4+7*x^3+4*x^2+3*x+1) / (x^10+364*x^5-1). - Colin Barker, Sep 26 2013
MAPLE
convert(sqrt(53), confrac, 30, cvgts): denom(cvgts); # Wesley Ivan Hurt, Dec 17 2013
MATHEMATICA
Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[53], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Jun 23 2011 *)
Denominator[Convergents[Sqrt[53], 30]] (* Vincenzo Librandi, Oct 24 2013 *)
LinearRecurrence[{0, 0, 0, 0, 364, 0, 0, 0, 0, 1}, {1, 3, 4, 7, 25, 357, 1096, 1453, 2549, 9100}, 30] (* Harvey P. Dale, Nov 13 2019 *)
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
STATUS
approved
Decimal expansion of (7+sqrt(53))/2.
+10
9
7, 1, 4, 0, 0, 5, 4, 9, 4, 4, 6, 4, 0, 2, 5, 9, 1, 3, 5, 5, 4, 8, 6, 5, 1, 2, 4, 5, 7, 6, 3, 5, 1, 6, 3, 9, 6, 8, 8, 8, 8, 3, 4, 8, 4, 1, 2, 8, 8, 2, 3, 8, 7, 1, 9, 1, 8, 9, 0, 9, 0, 8, 9, 5, 6, 4, 2, 0, 5, 7, 8, 6, 9, 3, 1, 2, 4, 5, 2, 5, 9, 1, 6, 6, 4, 7, 8, 9, 7, 0, 4, 5, 4, 0, 4, 6, 3, 3, 7, 6, 0, 9, 6, 3, 1
OFFSET
1,1
COMMENTS
Continued fraction expansion of (7+sqrt(53))/2 is A010727.
This is the shape of a 7-extension rectangle; see A188640 for definitions. [From Clark Kimberling, Apr 09 2011]
c^n = c * A054413(n-1) + A054413(n-2), where c = (7+sqrt(53))/2. - Gary W. Adamson, Apr 14 2024
FORMULA
Equals lim_{n->oo} S(n, sqrt(53))/S(n-1, sqrt(53)), with the S-Chebyshev polynomials (see A049310). - Wolfdieter Lang, Nov 15 2023
Positive solution of x^2 - 7*x - 1 = 0. - Hugo Pfoertner, Apr 14 2024
EXAMPLE
(7+sqrt(53))/2 = 7.14005494464025913554...
MATHEMATICA
r=7; t = (r + (4+r^2)^(1/2))/2; FullSimplify[t]
N[t, 130]
RealDigits[N[t, 130]][[1]]
RealDigits[(7+Sqrt[53])/2, 10, 120][[1]] (* Harvey P. Dale, Nov 03 2024 *)
PROG
(PARI) (7+sqrt(53))/2 \\ Charles R Greathouse IV, Jul 24 2013
CROSSREFS
Cf. A010506 (decimal expansion of sqrt(53)), A010727 (all 7's sequence).
Cf. A049310.
KEYWORD
nonn,cons,easy,changed
AUTHOR
Klaus Brockhaus, Apr 19 2010
STATUS
approved
Continued fraction for sqrt(53).
+10
4
7, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3, 14, 3, 1, 1, 3
OFFSET
0,1
EXAMPLE
7.280109889280518271097302491... = 7 + 1/(3 + 1/(1 + 1/(1 + 1/(3 + ...)))). - Harry J. Smith, Jun 06 2009
MATHEMATICA
ContinuedFraction[Sqrt[53], 300] (* Vladimir Joseph Stephan Orlovsky, Mar 07 2011 *)
PadRight[{7}, 120, {14, 3, 1, 1, 3}] (* Harvey P. Dale, May 22 2016 *)
PROG
(PARI) { allocatemem(932245000); default(realprecision, 21000); x=contfrac(sqrt(53)); for (n=0, 20000, write("b010139.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 06 2009
CROSSREFS
Cf. A010506 Decimal expansion. - Harry J. Smith, Jun 06 2009
KEYWORD
nonn,cofr
STATUS
approved
Decimal expansion of sqrt(635918528029).
+10
4
7, 9, 7, 4, 4, 5, 0, 0, 0, 0, 0, 2, 5, 0, 8, 0, 0, 9, 9, 5, 6, 7, 9, 5, 5, 8, 4, 5, 7, 7, 0, 2, 8, 2, 6, 7, 9, 1, 1, 8, 8, 3, 1, 4, 7, 5, 2, 4, 6, 2, 4, 2, 1, 7, 4, 8, 3, 7, 3, 9, 2, 0, 0, 9, 2, 3, 7, 7, 2, 6, 0, 4, 9, 3, 7, 1, 7, 8, 6, 4, 0, 9, 4, 7, 9, 3, 8, 5, 3, 3, 2, 5, 5, 2, 2, 9, 5, 9, 7, 7, 3, 9, 3, 0, 0
OFFSET
6,1
COMMENTS
Continued fraction expansion of sqrt(635918528029) is 797445 followed by (repeat 398722, 1, 1, 398722, 1594890).
sqrt(635918528029) = sqrt(17)*sqrt(53)*sqrt(193)*sqrt(3656953).
LINKS
EXAMPLE
sqrt(635918528029) = 797445.00000250800995679558...
MATHEMATICA
First[RealDigits[Sqrt[635918528029], 10, 120]] (* Paolo Xausa, Jan 09 2024 *)
CROSSREFS
Cf. A010473 (decimal expansion of sqrt(17)), A010506 (decimal expansion of sqrt(53)), A177272 (decimal expansion of sqrt(193)), A177273 (decimal expansion of sqrt(3656953)), A177274 (continued fraction expansion of (684125+sqrt(635918528029))/1033802), A177270 (decimal expansion of (684125+sqrt(635918528029))/1033802).
KEYWORD
cons,nonn
AUTHOR
Klaus Brockhaus, May 07 2010
STATUS
approved

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