cp's OEIS Frontend

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.

A346518 Total number of partitions of all n-multisets {1,2,...,n-j,1,2,...,j} into distinct multisets for 0 <= j <= n.

Original entry on oeis.org

1, 2, 5, 16, 53, 202, 826, 3724, 17939, 93390, 516125, 3042412, 18923139, 124368810, 857827458, 6208594458, 46937360868, 370335617694, 3039823038753, 25928519847988, 229285625745624, 2099543718917418, 19872430464012935, 194203934113959970, 1956736801957704866
Offset: 0

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Author

Alois P. Heinz, Jul 21 2021

Keywords

Comments

Also total number of factorizations of Product_{i=1..n-j} prime(i) * Product_{i=1..j} prime(i) into distinct factors for 0 <= j <= n.

Crossrefs

Antidiagonal sums of A346517.

Programs

  • Maple
    b:= proc(n) option remember; `if`(n=0, 1,
          add(b(n-j)*binomial(n-1, j-1), j=1..n))
        end:
    A:= proc(n, k) option remember; `if`(n add(A(n-j, j), j=0..n):
    seq(a(n), n=0..24);
  • Mathematica
    (* Q is A322770 *)
    Q[m_, n_] := Q[m, n] = If[n == 0, BellB[m], (1/2) (Q[m + 2, n - 1] +
         Q[m + 1, n - 1] - Sum[Binomial[n - 1, k] Q[m, k], {k, 0, n - 1}])];
    A[n_, k_] := Q[Abs[n - k], Min[n, k]];
    a[n_] := Sum[A[n - j, j], {j, 0, n}];
    Table[a[n], {n, 0, 24}] (* Jean-François Alcover, Apr 06 2022 *)

Formula

a(n) = Sum_{j=0..n} A045778(A002110(n-j)*A002110(j)).
a(n) = Sum_{j=0..n} A346517(n-j,j).