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 A259253 Primes of the form: 1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4 + sigma(n)^5 + sigma(n)^6. 3
 7, 1093, 55987, 5229043, 8108731, 917087137, 47446779661, 917087137, 4201025641, 31401724537, 141276239497, 3092313043, 47446779661, 31401724537, 141276239497, 654022685443, 141276239497, 141276239497, 265462278481, 47446779661, 100343116693, 4033516174507 (list; graph; refs; listen; history; text; internal format)
 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 FORMULA a(n) = A259251(A259252(n)). 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 Cf. A000203, A259251, A259252. Sequence in context: A101072 A203583 A259251 * A203871 A144927 A202133 Adjacent sequences:  A259250 A259251 A259252 * A259254 A259255 A259256 KEYWORD easy,nonn AUTHOR Robert Price, Jun 22 2015 STATUS approved

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Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)