OFFSET
1,3
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
FORMULA
G.f.: (conjectured) Sum_{n>=1} n*x^(n*(n+1)/2)/(1-x^(n*(n+1)/2)). - Joerg Arndt, Jan 30 2011
PROG
(PARI) A069972(n) = { n = 2*n; sumdiv(n, d, if(!(n%(1+d)), d, 0)); }; \\ Antti Karttunen, Mar 02 2023
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Apr 29 2002
STATUS
approved