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A259186
Primes in A259184.
3
7, 13, 43, 31, 211, 157, 307, 757, 307, 1483, 1723, 3541, 1723, 5113, 3907, 8191, 3541, 8011, 1723, 6007, 5113, 5113, 14281, 5113, 14281, 8011, 3541, 28057, 20593, 20593, 5113, 37831, 28057, 17293, 14281, 8011, 12433, 28057, 20593, 14281, 24181, 10303, 46441
OFFSET
1,1
COMMENTS
These primes are neither sorted nor uniqued. They are listed in the order found in A259184.
FORMULA
a(n) = A259184(A259185(n)).
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