OFFSET
4,6
LINKS
Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 4..650
MAPLE
b:= proc(n, p, i) option remember; `if`(n=0, p!,
`if`(i<1, 0, add(b(n-i*j, p+j, i-1)/j!, j=0..n/i)))
end:
a:= proc(n) local k; k:=4;
add(b(n-i*k, k, i-1)/k!, i=1..n/k)
end:
seq(a(n), n=4..40);
MATHEMATICA
b[n_, p_, i_] := b[n, p, i] = If[n == 0, p!, If[i<1, 0, Sum[b[n-i*j, p+j, i-1]/j!, {j, 0, n/i}]]]; a[n_] := (k=4; Sum[b[n-i*k, k, i-1]/k!, {i, 1, n/k}]); Table[a[n], {n, 4, 40}] (* Jean-François Alcover, Feb 10 2015, after Maple *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jun 09 2014
STATUS
approved