OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..200
FORMULA
a(n) = Sum_{j=0..n} (j-1)! * [x^(j-1)] exp(x + Sum_{i=1..n-j} (exp(i*x)-1)/i) for n > 0, a(0) = 1.
a(n) = Sum_{j=0..n} A305962(j,n-j).
MAPLE
b:= proc(n, k, m) option remember; `if`(n=0, 1,
add(b(n-1, k, max(m, j)), j=1..m+k))
end:
a:= n-> add(b(j, n-j, 1+j-n), j=0..n):
seq(a(n), n=0..25);
# second Maple program:
b:= (n, k)-> `if`(n=0, 1, (n-1)!*coeff(series(exp(x+add(
(exp(j*x)-1)/j, j=1..k)), x, n), x, n-1)):
a:= n-> add(b(j, n-j), j=0..n):
seq(a(n), n=0..25);
MATHEMATICA
b[n_, k_, m_] := b[n, k, m] = If[n == 0, 1, Sum[b[n - 1, k, Max[m, j]], {j, 1, m + k}]];
a[n_] := Sum[b[j, n - j, 1 + j - n], {j, 0, n}];
Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Nov 16 2022, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 15 2018
STATUS
approved