OFFSET
1,1
COMMENTS
These primes are neither sorted nor uniqued. They are listed in the order found in A259251.
LINKS
Robert Price, Table of n, a(n) for n = 1..885
MAPLE
with(numtheory): A259253:=n->`if`(isprime(1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4+sigma(n)^5+sigma(n)^6), 1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4 + sigma(n)^5 + sigma(n)^6, NULL): seq(A259253(n), n=1..100); # Wesley Ivan Hurt, Jul 09 2015
MATHEMATICA
Select[Table[1 + DivisorSigma[1, n] + DivisorSigma[1, n]^2 + DivisorSigma[1, n]^3 + DivisorSigma[1, n]^4 + DivisorSigma[1, n]^5 + DivisorSigma[1, n]^6, {n, 10000}], PrimeQ]
Select[Table[Cyclotomic[7, DivisorSigma[1, n]], {n, 10000}], PrimeQ]
Select[Table[Total[DivisorSigma[1, n]^Range[0, 6]], {n, 80}], PrimeQ] (* Harvey P. Dale, Oct 09 2020 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert Price, Jun 22 2015
STATUS
approved