OFFSET
1,2
COMMENTS
Numbers k such that k is a multiple of 1+A156552(k).
If k is a term, then also 2*k is present in this sequence, and vice versa.
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) - Antti Karttunen, Jul 28 2023
isA364550(n) = !(n%A005941(n));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 28 2023
STATUS
approved