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 A258997 #34 Oct 26 2018 20:39:31 %S A258997 0,0,0,0,0,0,0,0,1,0,0,0,4,2,0,0,0,12,12,4,0,0,0,32,54,32,3,0,0,0,80, %T A258997 216,192,30,7,0,0,0,192,810,1024,225,84,4,0,0,0,448,2916,5120,1500, %U A258997 756,56,12,0,0,0,1024,10206,24576,9375,6048,588,192,12,0 %N A258997 A(n,k) = pi-based antiderivative of n^k; square array A(n,k), n>=0, k>=0, read by antidiagonals. %H A258997 Alois P. Heinz, <a href="/A258997/b258997.txt">Antidiagonals n = 0..140, flattened</a> %F A258997 A(n,k) = A258851(n^k) = k * n^(k-1) * A258851(n). %e A258997 Square array A(n,k) begins: %e A258997 0, 0, 0, 0, 0, 0, 0, 0, ... %e A258997 0, 0, 0, 0, 0, 0, 0, 0, ... %e A258997 0, 1, 4, 12, 32, 80, 192, 448, ... %e A258997 0, 2, 12, 54, 216, 810, 2916, 10206, ... %e A258997 0, 4, 32, 192, 1024, 5120, 24576, 114688, ... %e A258997 0, 3, 30, 225, 1500, 9375, 56250, 328125, ... %e A258997 0, 7, 84, 756, 6048, 45360, 326592, 2286144, ... %e A258997 0, 4, 56, 588, 5488, 48020, 403368, 3294172, ... %p A258997 with(numtheory): %p A258997 d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]): %p A258997 A:= (n, k)-> `if`(k=0, 0, k*n^(k-1)*d(n)): %p A258997 seq(seq(A(n, h-n), n=0..h), h=0..14); %Y A258997 Rows n=0+1,2,3,4,8 give: A000004, A001787, A212697, A018215, A230539. %Y A258997 Columns k=0,1 give: A000004, A258851. %Y A258997 Main diagonal gives A258846. %Y A258997 Cf. A000720. %K A258997 nonn,tabl %O A258997 0,13 %A A258997 _Alois P. Heinz_, Jun 27 2015