This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A178705 Odd composite numbers q such that there exists a, 2<=a<=q-2, such that a^d == 1 mod q where d = A000265(q-1). Thus q is a strong pseudoprime in base a. 1
 49, 91, 121, 133, 169, 175, 217, 231, 247, 259, 301, 325, 341, 343, 361, 385, 403, 427, 435, 451, 469, 475, 481, 511, 529, 553, 559, 561, 589, 595, 637, 645, 651, 671, 679, 703, 715, 721, 763, 775, 781, 793, 805, 817, 841, 847, 861, 871, 889, 891, 925, 931, 949, 961, 973, 1001, 1015, 1027, 1035, 1045 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Odd composite numbers q such that gcd(A000010(q), A000265(q-1)) > 1. - Robert Israel, Dec 20 2017 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA a^d == 1 mod q EXAMPLE 18^3 == 1 mod 49 MAPLE filter:= proc(n)   if isprime(n) then return false fi;   igcd((n-1)/2^padic:-ordp(n-1, 2), numtheory:-phi(n)) > 1 end proc: select(filter, [seq(i, i=9..2000, 2)]); # Robert Israel, Dec 20 2017 CROSSREFS Cf. A000010, A000265. Sequence in context: A090825 A157342 A230226 * A118886 A198773 A108164 Adjacent sequences:  A178702 A178703 A178704 * A178706 A178707 A178708 KEYWORD nonn AUTHOR Karsten Meyer, Dec 26 2010 EXTENSIONS Corrected by Robert Israel, Dec 20 2017 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 21 01:46 EDT 2018. Contains 300994 sequences. (Running on oeis4.)