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A294717 Numbers k such that 2^((k-1)/3) == 1 (mod k) and (2*k-1)*(2^((k-1)/6)) == 1 (mod k). 7
1, 43, 109, 157, 229, 277, 283, 307, 397, 499, 643, 691, 733, 739, 811, 997, 1021, 1051, 1069, 1093, 1459, 1579, 1597, 1627, 1699, 1723, 1789, 1933, 2179, 2203, 2251, 2341, 2347, 2731, 2749, 2917, 2971, 3061, 3163, 3181, 3229, 3259, 3277, 3331, 3373, 3541, 4027 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Most of the elements of this sequence are prime. The "pseudoprimes" of these sequence are part of A244626.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Range[1, 6001, 6], # == 1 || PowerMod[2, (#-1)/3, #] == 1 && Mod[-PowerMod[2, (#-1)/6, #], #] == 1&] (* Jean-François Alcover, Nov 18 2018 *)
PROG
(PARI) is(n)=n%6==1 && Mod(2, n)^(n\3)==1 && (2*n-1)*Mod(2, n)^(n\6)==1 \\ Charles R Greathouse IV, Nov 08 2017
CROSSREFS
Sequence in context: A141857 A106923 A115586 * A001133 A292578 A139969
KEYWORD
nonn
AUTHOR
Jonas Kaiser, Nov 07 2017
STATUS
approved

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Last modified March 28 08:22 EDT 2024. Contains 371236 sequences. (Running on oeis4.)