OFFSET
1,6
COMMENTS
Order of partition is lcm of its parts.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..16384
FORMULA
Coefficient of x^n in expansion of Sum_{i divides n} mu(n/i)*Product_{j divides i} (1+x^j).
EXAMPLE
The a(36) = 6 partitions are (36), (18,12,6), (18,12,4,2), (18,12,3,2,1), (18,9,4,3,2), (12,9,6,4,3,2). - Gus Wiseman, Aug 01 2018
PROG
(PARI) A074971(n) = { my(q=0); fordiv(n, i, my(p=1); fordiv(i, j, p *= (1 + 'x^j)); q += moebius(n/i)*p); polcoeff(q, n); }; \\ Antti Karttunen, Dec 19 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Oct 05 2002
STATUS
approved