A064257 - OEIS

%I #11 Oct 17 2019 05:58:44

%S 306,7686,9900,24168,32778,68448,86160,107070,112236,148398,172998,

%T 207930,217770,221706,231546,250488,277548,292800,303378,306576,

%U 329208,354300,380130,398580,488616,490338,492798,501408,533388,559218,567828,605220,619980,640890

%N 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.

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

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

%H Amiram Eldar, <a href="/A064257/b064257.txt">Table of n, a(n) for n = 1..10000</a>

%t 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 *)

%Y Cf. A087788.

%K nonn

%O 1,1

%A _N. J. A. Sloane_, Sep 23 2001

%E Offset corrected and more terms added by _Amiram Eldar_, Oct 17 2019