A029563 Quasi-Carmichael numbers to base -3: squarefree composites n such that for every prime p that divides n, p+3 divides n+3.

165, 357, 1885, 2397, 3965, 9447, 11877, 30597, 37245, 49657, 57405, 73437, 75517, 76857, 106485, 127677, 146605, 155397, 187485, 211117, 223197, 223737, 301597, 304917, 312477, 378397, 406077, 413445, 460317, 543197, 728637, 737877, 765697

Offset: 1

Author

David W. Wilson

Keywords

• nonn

References

• J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 165, p. 53, Ellipses, Paris 2008.

Links

• Giovanni Resta, Table of n, a(n) for n = 1..2693 (terms < 10^12)
• Index entries for sequences related to Carmichael numbers.

Programs

Mathematica

qcp[n_, d_] := Block[{p, e}, {p, e} = Transpose@FactorInteger@n;
Length[p] > 1 && Max[e] == 1 && And @@ IntegerQ /@ ((n + d)/(p + d))]; Select[Range[10^6], qcp[#, 3] &] (* Giovanni Resta, May 21 2013 *)