OFFSET
1,3
EXAMPLE
MAPLE
with(combinat): a:=proc(n) local G, Gser: G:=1/product(1-x^j, j=1..numbpart(n-1)): Gser:=series(G, x=0, 20+numbpart(n)): coeff(Gser, x^numbpart(n)) end: seq(a(n), n=1..22); # Emeric Deutsch, Apr 23 2006
MATHEMATICA
a[n_] := SeriesCoefficient[1/Product[1 - x^j, {j, 1, PartitionsP[n - 1]}], {x, 0, PartitionsP[n]}];
Table[a[n], {n, 1, 20}] (* Jean-François Alcover, May 28 2024, after Emeric Deutsch *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Sep 29 2004
EXTENSIONS
More terms from Emeric Deutsch, Apr 23 2006
STATUS
approved