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 A370363 #21 Feb 19 2024 18:28:37 %S A370363 0,0,1,0,1,1,0,1,1,1,0,1,1,1,1,0,1,1,7,1,1,0,1,1,28,45,1,1,0,1,1,103, %T A370363 1063,401,1,1,0,1,1,376,22893,74296,4355,1,1,0,1,1,1384,503751, %U A370363 13080721,8182855,56127,1,1,0,1,1,5146,11432655,2443061876,15237712355,1305232804,836353,1,1 %N A370363 Number A(n,k) of partitions of [k*n] into n sets of size k having at least one set of consecutive numbers whose maximum (if k>0) is a multiple of k; square array A(n,k), n>=0, k>=0, read by antidiagonals. %H A370363 Alois P. Heinz, <a href="/A370363/b370363.txt">Antidiagonals n = 0..55, flattened</a> %H A370363 Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a> %F A370363 A(n,k) = A060540(n,k) - A370366(n,k) for n,k >= 1. %e A370363 A(3,2) = 7: 12|34|56, 12|35|46, 12|36|45, 13|24|56, 14|23|56, 15|26|34, 16|25|34. %e A370363 Square array A(n,k) begins: %e A370363 0, 0, 0, 0, 0, 0, ... %e A370363 1, 1, 1, 1, 1, 1, ... %e A370363 1, 1, 1, 1, 1, 1, ... %e A370363 1, 1, 7, 28, 103, 376, ... %e A370363 1, 1, 45, 1063, 22893, 503751, ... %e A370363 1, 1, 401, 74296, 13080721, 2443061876, ... %p A370363 A:= proc(n, k) option remember; `if`(k=0, signum(n), add( %p A370363 (-1)^(n-j+1)*binomial(n, j)*(k*j)!/(j!*k!^j), j=0..n-1)) %p A370363 end: %p A370363 seq(seq(A(n, d-n), n=0..d), d=0..10); %Y A370363 Columns k=0+1,2-3 give: A057427, A370253, A370358. %Y A370363 Rows n=0,1+2,3 give: A000004, A000012, A370487. %Y A370363 Main diagonal gives A370364. %Y A370363 Antidiagonal sums give A370365. %Y A370363 Cf. A060540, A370366. %K A370363 nonn,tabl %O A370363 0,19 %A A370363 _Alois P. Heinz_, Feb 16 2024