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A258430
Primes in A088580.
3
2, 5, 7, 13, 19, 13, 29, 19, 43, 37, 61, 43, 41, 31, 73, 61, 43, 97, 79, 73, 73, 73, 61, 97, 127, 97, 73, 97, 127, 109, 181, 113, 157, 103, 211, 193, 163, 109, 281, 241, 211, 181, 157, 313, 337, 241, 271, 139, 337, 193, 181, 223, 229, 151, 373, 193, 241, 379
OFFSET
1,1
COMMENTS
These primes are neither sorted nor uniqued. They are listed in the order found in A088580.
FORMULA
a(n) = A088580(A065512(n)). - Michel Marcus, Jun 04 2015
MAPLE
with(numtheory): A258430:=n->`if`(isprime(1+sigma(n)), 1+sigma(n), NULL): seq(A258430(n), n=1..300); # Wesley Ivan Hurt, Jul 09 2015
MATHEMATICA
Select[Table[1 + DivisorSigma[1, n], {n, 10000}], PrimeQ]
PROG
(Magma) [a: n in [1..300] | IsPrime(a) where a is 1 + SumOfDivisors(n)]; // Vincenzo Librandi, May 30 2015
(PARI) select(x->isprime(x), vector(200, n, 1+sigma(n))) \\ Michel Marcus, Jun 04 2015
CROSSREFS
Sequence in context: A160676 A169690 A144300 * A333242 A045353 A038985
KEYWORD
nonn
AUTHOR
Robert Price, May 29 2015
STATUS
approved