OFFSET
1,1
COMMENTS
See A005382 (primes p such that sigma(2p-1) = 2p).
LINKS
Jens Kruse Andersen, Table of n, a(n) for n = 1..10000
EXAMPLE
For n = 3; prime(3) = 5, a(3) = sigma(2*5-1) = sigma(9) = 13.
PROG
(Magma) [SumOfDivisors(2*p-1): p in PrimesUpTo(2000)]
(PARI) vector(100, n, sigma(2*prime(n)-1)) \\ Derek Orr, Sep 25 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jaroslav Krizek, Sep 24 2014
STATUS
approved