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A338337
Coefficient of x^(6*n)*y^(6*n)*z^(6*n) in the expansion of 1/(1-x-y^2-z^3).
2
1, 4620, 135795660, 5190977391600, 221838126928317900, 10086906430733029017120, 477156732636269771364879600, 23199870600247661786357661924000, 1150983828787218131441395889200471500, 57991163446756752913635026142306805792320, 2957727121295876265116937111814024549631408160
OFFSET
0,2
COMMENTS
The other diagonal coefficients are zero.
LINKS
FORMULA
a(n) = (11*n)! / ((2*n)! * (3*n)! * (6*n)!). - Vaclav Kotesovec, Oct 28 2020
MAPLE
a:= proc(n) local h; 1/(1-x-y^2-z^3); for h in [x, y, z]
do coeff(series(%, h, 1+6*n), h, 6*n) od
end:
seq(a(n), n=0..10); # Alois P. Heinz, Oct 23 2020
MATHEMATICA
nmax = 10; Flatten[{1, Table[Coefficient[Series[1/(1 - x - y^2 - z^3), {x, 0, 6*n}, {y, 0, 6*n}, {z, 0, 6*n}], x^(6*n)*y^(6*n)*z^(6*n)], {n, 1, nmax}]}] (* Vaclav Kotesovec, Oct 23 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 22 2020
EXTENSIONS
More terms from Alois P. Heinz, Oct 23 2020
STATUS
approved