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
Keywords
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
Programs
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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;