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A159841
Triangle T(n,k) = binomial(3*n+1, 2*n+k+1), read by rows.
4
1, 4, 1, 21, 7, 1, 120, 45, 10, 1, 715, 286, 78, 13, 1, 4368, 1820, 560, 120, 16, 1, 27132, 11628, 3876, 969, 171, 19, 1, 170544, 74613, 26334, 7315, 1540, 231, 22, 1, 1081575, 480700, 177100, 53130, 12650, 2300, 300, 25, 1, 6906900, 3108105, 1184040, 376740
OFFSET
0,2
COMMENTS
T(n,0) = A045721(n), T(2n,n) = A079590(n).
FORMULA
T(n,0) = 4*T(n-1,0) + 5*T(n-1,1) + T(n-1,2), T(n+1,k+1) = T(n,k) + 3*T(n,k+1) + 3*T(n,k+2) + T(n,k+3) for k >= 0.
EXAMPLE
Triangle begins:
1;
4, 1;
21, 7, 1;
120, 45, 10, 1;
715, 286, 78, 13, 1;
4368, 1820, 560, 120, 16, 1;
...
MATHEMATICA
f[n_, k_]:=Binomial[3n+1, 2n+k+1]; Table[ f[n, k], {n, 0, 9}, {k, 0, n}] // Flatten (* Robert G. Wilson v, May 31 2009 *)
PROG
(PARI) for(n=0, 10, for(k=0, n, print1(binomial(3*n+1, 2*n+k+1), ", "))) \\ G. C. Greubel, May 19 2018
(Magma) /* As triangle */ [[Binomial(3*n+1, 2*n+k+1): k in [0..n]]: n in [0..10]]; // G. C. Greubel, May 19 2018
CROSSREFS
Sequence in context: A144484 A121336 A126457 * A202550 A364760 A142472
KEYWORD
nonn,tabl
AUTHOR
Philippe Deléham, Apr 23 2009
EXTENSIONS
More terms from Robert G. Wilson v, May 31 2009
STATUS
approved