A292021 Lucas-Carmichael numbers that are congruent to 1 (mod 4).

20705, 80189, 120581, 1162349, 7274249, 8734109, 10260809, 14658349, 49412285, 90393029, 105818129, 110066669, 125532329, 256074029, 362868329, 366648281, 395032609, 434886605, 503733257, 558705449, 563601257, 574342145, 640057109, 939989609, 962529749

Offset

1,1

Comments

Most Lucas-Carmichael numbers are congruent to 3 (mod 4). Of the 9967 numbers less than 10^12 only 198 are congruent to 1 (mod 4).

Analogous to A185321 - Carmichael numbers that are congruent to 3 (mod 4).

Links

Amiram Eldar, Table of n, a(n) for n = 1..198 (terms below 10^12)

Mathematica

a=Select[Range[2, 10^6], !PrimeQ[#] && Union[Transpose[FactorInteger[#]][[2]]] == {1} && Union[Mod[# + 1, Transpose[FactorInteger[#]][[1]] + 1]]=={0} &] ; Select[a, Mod[#, 4]==1 &] (* after Richard Pinch and Jeffrey Shallit at A006972 *)

Crossrefs

Intersection of A006972 and A016813.

Cf. A110885, A185321.

Sequence in context: A247926 A107263 A237329 * A183631 A340175 A176771

Adjacent sequences: A292018 A292019 A292020 * A292022 A292023 A292024

Keyword

nonn

Author

Amiram Eldar, Sep 07 2017

Status

approved