A064257 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,41.

306, 7686, 9900, 24168, 32778, 68448, 86160, 107070, 112236, 148398, 172998, 207930, 217770, 221706, 231546, 250488, 277548, 292800, 303378, 306576, 329208, 354300, 380130, 398580, 488616, 490338, 492798, 501408, 533388, 559218, 567828, 605220, 619980, 640890

Offset

1,1

Comments

am+1, bm+1, cm+1 are primes and am | (N-1), bm | (N-1), cm |(N-1).

References

Harvey Dubner (harvey(AT)dubner.com), personal communication, Jun 27 2001.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

carmQ[n_] := CompositeQ[n] && Divisible[n - 1, CarmichaelLambda[n]]; Select[Range[10^5], AllTrue[(v = {1, 2, 41}*# + 1), PrimeQ] && carmQ[Times @@ v] &] (* Amiram Eldar, Oct 17 2019 *)

Crossrefs

Cf. A087788.

Sequence in context: A206679 A172966 A223073 * A221854 A221724 A023908

Adjacent sequences: A064254 A064255 A064256 * A064258 A064259 A064260

Keyword

nonn

Author

N. J. A. Sloane, Sep 23 2001

Extensions

Offset corrected and more terms added by Amiram Eldar, Oct 17 2019

Status

approved