The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A331424 Prime numbers p such that p^2 divides 31^(p-1) - 1. 2
 7, 79, 6451, 2806861 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Richard Fischer, Fermatquotienten von 2 bis 1052, Dec 19 2019. Wikipedia, Wieferich prime PROG (PARI) forprime(p=2, 1e8, if(Mod(31, p^2)^(p-1)==1, print1(p", "))) CROSSREFS Wieferich primes to base b: A001220 (b=2), A014127 (b=3), A123692 (b=5), A123693 (b=7), A128667 (b=13), A128668 (b=17), A090968 (b=19), A128669 (b=23), this sequence (b=31), A331426 (b=37), A331427 (b=41). Cf. A039951. Sequence in context: A113034 A267798 A201704 * A052385 A093947 A222137 Adjacent sequences:  A331421 A331422 A331423 * A331425 A331426 A331427 KEYWORD nonn,more AUTHOR Seiichi Manyama, Jan 16 2020 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.

Last modified January 18 06:22 EST 2021. Contains 340250 sequences. (Running on oeis4.)