A029569 Quasi-Carmichael numbers to base -9: squarefree composites n such that prime p|n ==> p+9|n+9.

231, 2679, 18471, 24311, 61171, 71799, 84271, 107371, 112871, 140151, 150071, 305359, 364791, 420391, 483351, 854845, 948631, 966671, 1003191, 1209745, 1260791, 1327911, 1451791, 1675511, 1691351, 1870167, 1982391, 2400935, 2721535

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Links

• Giovanni Resta, Table of n, a(n) for n = 1..2185 (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[#, 9] &] (* Giovanni Resta, May 21 2013 *)