OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..8192
FORMULA
PROG
(PARI)
A005941(n) = { my(f=factor(n), p, p2=1, res=0); for(i=1, #f~, p = 1 << (primepi(f[i, 1])-1); res += (p * p2 * (2^(f[i, 2])-1)); p2 <<= f[i, 2]); (1+res) }; \\ (After David A. Corneth's program for A156552)
memoA364574 = Map();
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Aug 05 2023
STATUS
approved