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 A246720 #18 Dec 07 2020 10:07:50 %S A246720 1,1,0,1,1,0,1,0,1,0,1,1,1,1,0,1,0,2,0,1,0,1,1,0,2,1,1,0,1,0,1,1,3,0, %T A246720 1,0,1,1,0,2,0,3,1,1,0,1,0,1,0,2,0,4,0,1,0,1,0,1,1,1,2,1,4,1,1,0,1,1, %U A246720 0,1,2,0,3,0,5,0,1,0,1,1,2,0,1,2,0,3,0,5,1,1,0 %N A246720 Number A(n,k) of partitions of n into parts of the k-th list of distinct parts in the order given by A246688; square array A(n,k), n>=0, k>=0, read by antidiagonals. %C A246720 The first lists of distinct parts in the order given by A246688 are: 0:[], 1:[1], 2:[2], 3:[1,2], 4:[3], 5:[1,3], 6:[4], 7:[1,4], 8:[2,3], 9:[5], 10:[1,2,3], 11:[1,5], 12:[2,4], 13:[6], 14:[1,2,4], 15:[1,6], 16:[2,5], 17:[3,4], 18:[7], 19:[1,2,5], 20:[1,3,4], ... . %H A246720 Alois P. Heinz, <a href="/A246720/b246720.txt">Antidiagonals n = 0..140, flattened</a> %e A246720 Square array A(n,k) begins: %e A246720 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... %e A246720 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, ... %e A246720 0, 1, 1, 2, 0, 1, 0, 1, 1, 0, 2, 1, 1, 0, 2, ... %e A246720 0, 1, 0, 2, 1, 2, 0, 1, 1, 0, 3, 1, 0, 0, 2, ... %e A246720 0, 1, 1, 3, 0, 2, 1, 2, 1, 0, 4, 1, 2, 0, 4, ... %e A246720 0, 1, 0, 3, 0, 2, 0, 2, 1, 1, 5, 2, 0, 0, 4, ... %e A246720 0, 1, 1, 4, 1, 3, 0, 2, 2, 0, 7, 2, 2, 1, 6, ... %e A246720 0, 1, 0, 4, 0, 3, 0, 2, 1, 0, 8, 2, 0, 0, 6, ... %e A246720 0, 1, 1, 5, 0, 3, 1, 3, 2, 0, 10, 2, 3, 0, 9, ... %e A246720 0, 1, 0, 5, 1, 4, 0, 3, 2, 0, 12, 2, 0, 0, 9, ... %e A246720 0, 1, 1, 6, 0, 4, 0, 3, 2, 1, 14, 3, 3, 0, 12, ... %p A246720 b:= proc(n, i) b(n, i):= `if`(n=0, [[]], `if`(i>n, [], %p A246720 [map(x->[i, x[]], b(n-i, i+1))[], b(n, i+1)[]])) %p A246720 end: %p A246720 f:= proc() local i, l; i, l:=0, []; %p A246720 proc(n) while n>=nops(l) %p A246720 do l:=[l[], b(i, 1)[]]; i:=i+1 od; l[n+1] %p A246720 end %p A246720 end(): %p A246720 g:= proc(n, l) option remember; `if`(n=0, 1, `if`(l=[], 0, %p A246720 add(g(n-l[-1]*j, subsop(-1=NULL, l)), j=0..n/l[-1]))) %p A246720 end: %p A246720 A:= (n, k)-> g(n, f(k)): %p A246720 seq(seq(A(n, d-n), n=0..d), d=0..16); %t A246720 b[n_, i_] := b[n, i] = If[n == 0, {{}}, If[i > n, {}, Join[Prepend[#, i]& /@ b[n - i, i + 1], b[n, i + 1]]]]; %t A246720 f = Module[{i = 0, l = {}}, Function[n, While[ n >= Length[l], l = Join[l, b[i, 1]]; i++ ]; l[[n + 1]]]]; %t A246720 g[n_, l_] := g[n, l] = If[n == 0, 1, If[l == {}, 0, Sum[g[n - l[[-1]] j, ReplacePart[l, -1 -> Nothing]], {j, 0, n/l[[-1]]}]]]; %t A246720 A[n_, k_] := g[n, f[k]]; %t A246720 Table[Table[A[n, d - n], {n, 0, d}], {d, 0, 16}] // Flatten (* _Jean-François Alcover_, Dec 07 2020, after _Alois P. Heinz_ *) %Y A246720 Columns k=0-11, 13-20, 23 give: A000007, A000012, A059841, A008619, A079978, A008620, A121262, A008621, A103221, A079998, A001399, A002266(n+5), A079979, A008642, A097992, A008616, A008679, A082784, A000115, A025767, A008676. %Y A246720 Main diagonal gives A246721. %Y A246720 Cf. A246688, A246690 (the same for compositions). %K A246720 nonn,tabl %O A246720 0,18 %A A246720 _Alois P. Heinz_, Sep 02 2014