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.
%I A318257 #9 Aug 26 2018 05:31:22 %S A318257 1,0,1,0,1,126,0,1,3003,126126,0,1,107882,23279256,488864376,0,1, %T A318257 3321890,5319906900,412275623760,5194672859376,0,1,107746281, %U A318257 1394769716340,369277150181940,14687937509885640,123378675083039376 %N 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. %e A318257 [0] [1] %e A318257 [1] [0, 1] %e A318257 [2] [0, 1, 126] %e A318257 [3] [0, 1, 3003, 126126] %e A318257 [4] [0, 1, 107882, 23279256, 488864376] %e A318257 [5] [0, 1, 3321890, 5319906900, 412275623760, 5194672859376] %p A318257 CL := p -> PolynomialTools:-CoefficientList(p, x): %p A318257 FL := p -> ListTools:-Flatten(p): %p A318257 f := z -> (1/5)*(exp(z)+2*(+exp(1/4*z*(5^(1/2)-1))*cos(1/4*z*2^(1/2)* %p A318257 (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)))): %p A318257 gf := exp(x*(f(z)-1)): ser := series(gf, z, 48): %p A318257 FL([seq(CL(sort(expand((5*n)!*coeff(ser, z, n*5)), [x], ascending)),n=0..7)]); %Y A318257 Cf. A048993 (m=1), A156289 (m=2), A291451 (m=3), A291452 (m=4), this seq (m=5). %K A318257 nonn,tabl %O A318257 0,6 %A A318257 _Peter Luschny_, Aug 22 2018