This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A130060 Primes p such that p^2 divides 3^p - 2^p - 1; or primes in A127074(n). 4
 2, 3, 7, 179, 619, 17807 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The prime p divides 3^p - 2^p - 1. Quotients (3^p - 2^p - 1)/p, where p = Prime[n], are listed in A127071. - Alexander Adamchuk, Jan 31 2008 a(7) > 10^9. [From D. S. McNeil, Mar 16 2009] LINKS MATHEMATICA Do[ n=Prime[k]; f=PowerMod[3, n, n^2] - PowerMod[2, n, n^2] - 1; If[ IntegerQ[ f/n^2 ], Print[n] ], {k, 1, 100000} ] CROSSREFS Cf. A127071, A127072, A127073, A127074 = numbers n such that n^2 divides 3^n - 2^n - 1. Cf. A130058, A130059, A130061, A130062, A130063. Sequence in context: A103405 A087311 A053924 * A224894 A266269 A053942 Adjacent sequences:  A130057 A130058 A130059 * A130061 A130062 A130063 KEYWORD hard,more,nonn AUTHOR Alexander Adamchuk, May 05 2007 EXTENSIONS 2 more terms found by Ryan Propper, Jan 01 2008. Incorrect a(7), a(8) removed by D. S. McNeil, Mar 16 2009. (The old version was 2,3,7,179,619,17807,135433,1376257.) 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 February 23 12:03 EST 2019. Contains 320431 sequences. (Running on oeis4.)