OFFSET
1,1
COMMENTS
These primes are neither sorted nor uniqued. They are listed in the order found in A259184.
LINKS
Robert Price, Table of n, a(n) for n = 1..1737
MAPLE
with(numtheory): A259186:=n->`if`(isprime(1 - sigma(n) + sigma(n)^2), 1 - sigma(n) + sigma(n)^2, NULL): seq(A259186(n), n=1..200); # Wesley Ivan Hurt, Jul 09 2015
MATHEMATICA
Select[Table[1 - DivisorSigma[1, n] + DivisorSigma[1, n]^2, {n, 10000}], PrimeQ]
Select[Table[Cyclotomic[6, DivisorSigma[1, n]], {n, 10000}], PrimeQ]
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert Price, Jun 20 2015
STATUS
approved