A246720 - OEIS

%I #18 Dec 07 2020 10:07:50

%S 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 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 0,1,2,0,3,0,5,0,1,0,1,1,2,0,1,2,0,3,0,5,1,1,0

%N 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 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 Alois P. Heinz, <a href="/A246720/b246720.txt">Antidiagonals n = 0..140, flattened</a>

%e Square array A(n,k) begins:

%e   1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1,  1, ...

%e   0, 1, 0, 1, 0, 1, 0, 1, 0, 0,  1, 1, 0, 0,  1, ...

%e   0, 1, 1, 2, 0, 1, 0, 1, 1, 0,  2, 1, 1, 0,  2, ...

%e   0, 1, 0, 2, 1, 2, 0, 1, 1, 0,  3, 1, 0, 0,  2, ...

%e   0, 1, 1, 3, 0, 2, 1, 2, 1, 0,  4, 1, 2, 0,  4, ...

%e   0, 1, 0, 3, 0, 2, 0, 2, 1, 1,  5, 2, 0, 0,  4, ...

%e   0, 1, 1, 4, 1, 3, 0, 2, 2, 0,  7, 2, 2, 1,  6, ...

%e   0, 1, 0, 4, 0, 3, 0, 2, 1, 0,  8, 2, 0, 0,  6, ...

%e   0, 1, 1, 5, 0, 3, 1, 3, 2, 0, 10, 2, 3, 0,  9, ...

%e   0, 1, 0, 5, 1, 4, 0, 3, 2, 0, 12, 2, 0, 0,  9, ...

%e   0, 1, 1, 6, 0, 4, 0, 3, 2, 1, 14, 3, 3, 0, 12, ...

%p b:= proc(n, i) b(n, i):= `if`(n=0, [[]], `if`(i>n, [],

%p       [map(x->[i, x[]], b(n-i, i+1))[], b(n, i+1)[]]))

%p     end:

%p f:= proc() local i, l; i, l:=0, [];

%p       proc(n) while n>=nops(l)

%p         do l:=[l[], b(i, 1)[]]; i:=i+1 od; l[n+1]

%p       end

%p     end():

%p g:= proc(n, l) option remember; `if`(n=0, 1, `if`(l=[], 0,

%p       add(g(n-l[-1]*j, subsop(-1=NULL, l)), j=0..n/l[-1])))

%p     end:

%p A:= (n, k)-> g(n, f(k)):

%p seq(seq(A(n, d-n), n=0..d), d=0..16);

%t 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 f = Module[{i = 0, l = {}}, Function[n, While[ n >= Length[l], l = Join[l, b[i, 1]]; i++ ]; l[[n + 1]]]];

%t 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 A[n_, k_] := g[n, f[k]];

%t Table[Table[A[n, d - n], {n, 0, d}], {d, 0, 16}] // Flatten (* _Jean-François Alcover_, Dec 07 2020, after _Alois P. Heinz_ *)

%Y 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 Main diagonal gives A246721.

%Y Cf. A246688, A246690 (the same for compositions).

%K nonn,tabl

%O 0,18

%A _Alois P. Heinz_, Sep 02 2014