OFFSET
0,7
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..10000
FORMULA
Coefficient of x^n in expansion of 1/Product_{d is prime divisor of n} (1-x^d). - Vladeta Jovovic, Apr 11 2004
MAPLE
with(numtheory):
a:= proc(n) local b, l; l:= sort([factorset(n)[]]):
b:= proc(m, i) option remember; `if`(m=0, 1, `if`(i<1, 0,
b(m, i-1)+`if`(l[i]>m, 0, b(m-l[i], i))))
end; forget(b):
b(n, nops(l))
end:
seq(a(n), n=0..100); # Alois P. Heinz, Feb 05 2014
MATHEMATICA
a[0] = 1; a[n_] := SeriesCoefficient[1/Product[1-x^d, {d, FactorInteger[n][[All, 1]]}], {x, 0, n}]; Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Jul 30 2015, after Vladeta Jovovic *)
CROSSREFS
KEYWORD
AUTHOR
Naohiro Nomoto, Jan 26 2002
EXTENSIONS
More terms from Sascha Kurz, Mar 23 2002
Corrected by Vladeta Jovovic, Apr 11 2004
STATUS
approved