OFFSET
1,8
COMMENTS
Equally: Number of divisors d of n such that d-1 is an odd prime.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..15120
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..100000
MATHEMATICA
Array[DivisorSum[#, 1 &, And[EvenQ@ #, PrimeQ[# - 1]] &] &, 105] (* Michael De Vlieger, Jan 04 2019 *)
PROG
(PARI) A322977(n) = sumdiv(n, d, (!(d%2))*isprime(d-1));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 04 2019
STATUS
approved