A346428 Total number of partitions of all n-multisets {0,...,0,1,2,...,j} for 0 <= j <= n.
1, 2, 6, 17, 53, 180, 683, 2866, 13219, 66307, 358532, 2074229, 12761831, 83086064, 570017222, 4106269668, 30965072776, 243778358992, 1998878586251, 17034471643814, 150591119435358, 1378657063570498, 13050460812585580, 127553991370245410, 1285578058726241427
Offset: 0
Keywords
Examples
a(2) = 6: 00, 0|0, 01, 0|1, 12, 1|2. a(3) = 17: 000, 0|00, 0|0|0, 001, 00|1, 0|01, 0|0|1, 012, 0|12, 02|1, 01|2, 0|1|2, 123, 1|23, 13|2, 12|3, 1|2|3.
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..576
Programs
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Maple
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, combinat[numbpart](n), add(b(n-j, i-1), j=0..n))) end: a:= n-> add(add(S(n-i, j)*b(i, j), j=0..n-i), i=0..n): seq(a(n), n=0..25);
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Mathematica
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, PartitionsP[n], Sum[b[n - j, i - 1], {j, 0, n}]]]; a[n_] := Sum[Sum[S[n - i, j]*b[i, j], {j, 0, n - i}], {i, 0, n}]; Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Mar 12 2022, after Alois P. Heinz *)
Formula
a(n) = Sum_{j=0..n} A346426(n-j,j).
Comments