A346521 Total number of partitions of all n-multisets {0,...,0,1,2,...,j} into distinct multisets for 0 <= j <= n.

1, 2, 5, 15, 46, 161, 624, 2669, 12483, 63261, 344631, 2005058, 12390086, 80945545, 556896913, 4021109557, 30382294412, 239589006143, 1967343509525, 16786587081641, 148561276135546, 1361378815644787, 12897870827339021, 126158299918183469, 1272377007364596242

Offset

0,2

Comments

Also total number of factorizations of 2^(n-j) * Product_{i=1..j} prime(i+1) into distinct factors for 0 <= j <= n; a(2) = 5: 4, 2*3, 6, 3*5, 15; a(3) = 15: 2*4, 8, 3*4, 2*6, 12, 2*3*5, 5*6, 3*10, 2*15, 30, 3*5*7, 7*15, 5*21, 3*35, 105.

Links

Alois P. Heinz, Table of n, a(n) for n = 0..576

Formula

a(n) = Sum_{j=0..n} A346520(n-j,j).

a(n) = Sum_{j=0..n} A045778(A000079(n-j)*A070826(j+1)).

Example

a(2) = 5: 00, 01, 0|1, 12, 1|2.
a(3) = 15: 000, 0|00, 001, 00|1, 0|01, 012, 0|12, 02|1, 01|2, 0|1|2, 123, 1|23, 13|2, 12|3, 1|2|3.

Maple

g:= proc(n) option remember; `if`(n=0, 1, add(g(n-j)*add(
     `if`(d::odd, d, 0), d=numtheory[divisors](j)), j=1..n)/n)
    end:
s:= proc(n) option remember; expand(`if`(n=0, 1,
      x*add(s(n-j)*binomial(n-1, j-1), j=1..n)))
    end:
S:= proc(n, k) option remember; coeff(s(n), x, k) end:
b:= proc(n, i) option remember; `if`(n=0, 1,
     `if`(i=0, g(n), add(b(n-j, i-1), j=0..n)))
    end:
A:= (n, k)-> add(S(k, j)*b(n, j), j=0..k):
a:= n-> add(A(n-j, j), j=0..n):
seq(a(n), n=0..24);

Mathematica

g[n_] := g[n] = If[n == 0, 1, Sum[g[n - j]*Sum[If[OddQ[d], d, 0], {d, Divisors[j]}], {j, 1, n}]/n];
s[n_] := s[n] = Expand[If[n == 0, 1, x*Sum[s[n - j]*Binomial[n - 1, j - 1], {j, 1, n}]]];
S[n_, k_] := S[n, k] = Coefficient[s[n], x, k];
b[n_, i_] := b[n, i] = If[n == 0, 1, If[i == 0, g[n], Sum[b[n - j, i - 1], {j, 0, n}]]];
A[n_, k_] := Sum[S[k, j]*b[n, j], {j, 0, k}];
a[n_] := Sum[A[n - j, j], {j, 0, n}];
Table[a[n], {n, 0, 24}] (* Jean-François Alcover, Jul 31 2021, after Alois P. Heinz *)

Crossrefs

Antidiagonal sums of A346520.

Cf. A000009, A000040, A000079, A000110, A045778, A070826, A346428.

Sequence in context: A268648 A148360 A148361 * A148362 A143094 A308274

Adjacent sequences: A346518 A346519 A346520 * A346522 A346523 A346524

Keyword

nonn

Author

Alois P. Heinz, Jul 21 2021

Status

approved