A029561 Quasi-Carmichael numbers to base 2: squarefree composites n such that prime p|n ==> p-2|n-2.

1595, 6785, 53867, 67727, 102377, 296003, 740027, 961877, 998867, 1048817, 1270055, 1365377, 4086227, 7715567, 12266267, 15017921, 24960245, 33759467, 34918697, 36265385, 38342397, 41048777, 44535647, 48056087, 56264987, 58515347

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

These are called 2-Korselt numbers by Beouallegue et al.

Links

• Giovanni Resta, Table of n, a(n) for n = 1..393 (terms < 10^12)
• Index entries for sequences related to Carmichael numbers.
• K. Bouallegue, O. Echi, R. G. E. Pinch, Korselt numbers and sets, Int. J. Numb. Theory 6 (2) (2010) 257-269

Crossrefs

Cf. A120944, A002997.

Programs

Mathematica

qcm[n_, d_] := Block[{p, e}, {p, e} = Transpose@FactorInteger@n; Length[p] > 1 && Max[e] == 1 && ! MemberQ[p, d] && Max@ Mod[n-d, p-d] == 0]; Select[Range[10^5],  qcm[#, 2] &] (* Giovanni Resta, May 21 2013 *)