This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A178900 First nonzero value of a^(p-1) - 1 mod p^2, for a > 0 coprime to the n-th Wieferich prime p. 2
 341016, 24577 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS It is believed that a(n) = 3^(p-1) - 1 mod p^2 for all n, where p = A001220(n). See additional comments, references, links and cross-references in A001220. LINKS A. Ostafe and I. Shparlinski (2010), Pseudorandomness and Dynamics of Fermat Quotients FORMULA a(n) = A178815(A000720(p))^(p-1) - 1 mod p^2, where p = A001220(n). a(n) mod p = A178844(A000720(p)), where p = A001220(n). EXAMPLE The first Wieferich prime is 1093 and a^1092 - 1 mod 1093^2 = 0, 0, 341016 for a = 1, 2, 3, so a(1) = 341016. CROSSREFS Cf. A001220, A178815, A178844. Sequence in context: A182132 A182515 A236703 * A159462 A151559 A151563 Adjacent sequences:  A178897 A178898 A178899 * A178901 A178902 A178903 KEYWORD bref,hard,more,nonn AUTHOR Jonathan Sondow, Jun 23 2010 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 October 14 07:31 EDT 2019. Contains 327995 sequences. (Running on oeis4.)