login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

OEIS Wiki, Cyclotomic Polynomials at x=n, n! and sigma(n)

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]

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 16 02:52 EDT 2019. Contains 328038 sequences. (Running on oeis4.)