OFFSET
1,4
COMMENTS
Number of terms of A005097 which are less than n that divide n.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
PROG
(PARI) A305818(n) = sumdiv(n, d, (d<n)*isprime(d+d+1));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 15 2018
STATUS
approved