This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A180061 Numbers n such that (2^(2^n mod n) mod n)=4. 1
 5, 6, 7, 9, 11, 12, 13, 17, 19, 21, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 63, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 121, 127, 131, 133, 137, 139, 149, 151, 157, 163, 167, 172, 173, 179, 181, 190, 191, 193, 196, 197, 199, 211 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The composite terms in this sequence start 6, 9, 12, 21, 63, 121, 133, 172, 190, 196,.. - R. J. Mathar, Jan 14 2011 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 FORMULA A180060(a(n))=4. MATHEMATICA Select[Range[300], PowerMod[2, PowerMod[2, #, #], #]==4&] (* Harvey P. Dale, Sep 08 2016 *) PROG (PARI) s=[]; for(n=1, 1000, if((2^(2^n%n)%n)==4, s=concat(s, n))); s \\ Colin Barker, Jun 27 2014 CROSSREFS Cf. A000040, A000079, A179976, A180060. Sequence in context: A279195 A232710 A132829 * A196029 A096820 A175154 Adjacent sequences:  A180058 A180059 A180060 * A180062 A180063 A180064 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Jan 14 2011 EXTENSIONS Terms corrected by R. J. Mathar, Jan 14 2011 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 17 18:58 EDT 2019. Contains 328127 sequences. (Running on oeis4.)