cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A318257 Triangle read by rows, expansion of the e.g.f. given below related to partitions of {1,2,...,5n} into sets of size 5, nonzero coefficients of z.

Original entry on oeis.org

1, 0, 1, 0, 1, 126, 0, 1, 3003, 126126, 0, 1, 107882, 23279256, 488864376, 0, 1, 3321890, 5319906900, 412275623760, 5194672859376, 0, 1, 107746281, 1394769716340, 369277150181940, 14687937509885640, 123378675083039376
Offset: 0

Views

Author

Peter Luschny, Aug 22 2018

Keywords

Examples

			[0] [1]
[1] [0, 1]
[2] [0, 1,     126]
[3] [0, 1,    3003,     126126]
[4] [0, 1,  107882,   23279256,    488864376]
[5] [0, 1, 3321890, 5319906900, 412275623760, 5194672859376]
		

Crossrefs

Cf. A048993 (m=1), A156289 (m=2), A291451 (m=3), A291452 (m=4), this seq (m=5).

Programs

  • Maple
    CL := p -> PolynomialTools:-CoefficientList(p, x):
    FL := p -> ListTools:-Flatten(p):
    f := z -> (1/5)*(exp(z)+2*(+exp(1/4*z*(5^(1/2)-1))*cos(1/4*z*2^(1/2)*
    (5+5^(1/2))^(1/2))+exp(-1/4*z*(5^(1/2)+1))*cos(1/4*z*2^(1/2)*(5-5^(1/2))^(1/2)))):
    gf := exp(x*(f(z)-1)): ser := series(gf, z, 48):
    FL([seq(CL(sort(expand((5*n)!*coeff(ser, z, n*5)), [x], ascending)),n=0..7)]);