

A101187


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


3



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
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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

Bruno Berselli, Table of n, a(n) for n = 1..1000
Harvey Dubner, Journal of Integer Sequences, Vol. 5 (2002) Article 02.2.1, Carmichael Numbers of the form (6m+1)(12m+1)(18m+1).
G. 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: A129286 A083450 A136974 * A277550 A070373 A231000
Adjacent sequences: A101184 A101185 A101186 * A101188 A101189 A101190


KEYWORD

nonn


AUTHOR

Gerard P. Michon, Dec 03 2004


STATUS

approved



