A101187 Values of m for which (6m+1)(12m+1)(18m+1) is a Carmichael number.

1, 5, 6, 11, 15, 22, 33, 35, 45, 51, 55, 56, 61, 85, 96, 100, 103, 105, 115, 121, 195, 206, 216, 225, 242, 255, 276, 370, 380, 426, 455, 470, 506, 510, 511, 550, 561, 588, 609, 628, 661, 700, 710, 741, 800, 805, 825, 871, 920, 930, 975, 1025, 1060, 1115, 1140

Offset

1,2

Comments

A046025 is a subsequence giving the values of m for which the three factors are prime, which is a sufficient condition for the product (6m+1)(12m+1)(18m+1) to be a Carmichael number.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Bruno Berselli)

Harvey Dubner, Carmichael Numbers of the form (6m+1)(12m+1)(18m+1), Journal of Integer Sequences, Vol. 5 (2002) Article 02.2.1.

Gérard P. Michon, Generic Carmichael Numbers.

Mathematica

CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 1200, CarmichaelNbrQ[(6# + 1)(12# + 1)(18# + 1)] &] (* Robert G. Wilson v, Aug 23 2012 *)

Prog

(Magma) [n: n in [1..1200] | IsOne(t mod CarmichaelLambda(t)) where t is (6*n+1)*(12*n+1)*(18*n+1)]; // Bruno Berselli, Jan 22 2013

Crossrefs

Cf. A002997 (Carmichael numbers), A046025 (subsequence), A101186.

See also A065703.

Sequence in context: A334813 A083450 A136974 * A277550 A070373 A231000

Adjacent sequences: A101184 A101185 A101186 * A101188 A101189 A101190

Keyword

nonn

Author

Gerard P. Michon, Dec 03 2004

Status

approved