A029567 Quasi-Carmichael numbers to base -7: squarefree composites n such that prime p|n ==> p+7|n+7.

273, 2093, 2387, 2585, 6545, 7553, 11433, 11753, 16653, 19865, 33473, 34265, 35105, 37433, 53345, 72065, 88193, 99209, 120089, 124733, 136793, 149753, 155873, 158723, 159581, 164423, 198653, 203573, 232193, 257033, 263993, 284303, 349265, 372053

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Links

• Giovanni Resta, Table of n, a(n) for n = 1..7312 (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[#, 7] &] (* Giovanni Resta, May 21 2013 *)