A187923 Numbers n of the form 4*k+3 such that 2^(m-1) == 1 (mod m) where m = (2*n-1)*n.

47, 67, 2731, 2887, 5827, 13567, 41647, 44851, 46051, 47911, 59671, 61231, 66571, 78439, 90107, 109891, 138007, 141067, 144451, 164011, 183907, 321091, 406591, 430987, 460531, 501187, 513731, 532027, 537587, 554731, 598687, 673207, 677447

Offset

1,1

Comments

The first composite is 45812984491. [Charles R Greathouse IV, Mar 20 2011]

Links

Table of n, a(n) for n=1..33.

Mathematica

Select[4*Range[200000]+3, PowerMod[2, (2#-1)#-1, #(2#-1)]==1&] (* Harvey P. Dale, Mar 01 2017 *)

Crossrefs

Subsequence of A004767 (4*k+3).

Sequence in context: A106874 A245745 A023331 * A103012 A166958 A112056

Adjacent sequences: A187920 A187921 A187922 * A187924 A187925 A187926

Keyword

nonn

Author

Alzhekeyev Ascar M, Mar 16 2011

Status

approved