OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..500 (terms 1..100 from Harry J. Smith)
FORMULA
sigma(a(n)) = A065403(n).
EXAMPLE
46 cases below 10^12; for M a Mersenne prime, (M+1)/2 is here: M=8191, 4096=(M+1)/2.
PROG
(PARI) { n=0; for (m=1, 10^9, if (isprime(m), next); x=sigma(m^2); if (isprime(x), write("b065404.txt", n++, " ", m^2); if (n==100, return)) ) } \\ Harry J. Smith, Oct 18 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Nov 06 2001
STATUS
approved