A242981 Carmichael numbers of the form (6*k + 1)*(12*k + 1)*(18*k + 1), where only one of the three numbers 6*k + 1, 12*k + 1, 18*k + 1 is prime.

13992265, 1504651681, 14782305601, 292869912385, 2387706608354185, 4484354372982001, 70895950685971489, 807481759780458361, 1659264916949696161, 118023300545190612481, 140695625117781970705, 11710597360056333492601, 19818019625768288167321

Offset

1,1

Links

Giovanni Resta, Table of n, a(n) for n = 1..26 (terms < 4*10^33)

Carlos Rivera, Puzzle 739

Eric Weisstein's World of Mathematics, Carmichael Number

Index entries for sequences related to Carmichael numbers

Prog

(Magma) lst:=[]; for k in [1..2482095] do t:={n: n in [1..3] | IsPrime(6*k*n+1)}; if #Set(t) eq 1 then c:=&*[6*k*n+1: n in [1..3]]; if IsOne(c mod CarmichaelLambda(c)) then lst:=Append(lst, c); end if; end if; end for; lst;

Crossrefs

Cf. A002997, A033502, A242980.

Sequence in context: A116148 A210085 A251521 * A210133 A216700 A234411

Adjacent sequences: A242978 A242979 A242980 * A242982 A242983 A242984

Keyword

nonn

Author

Arkadiusz Wesolowski, May 28 2014

Status

approved