A029559 Quasi-Carmichael numbers to base 4: squarefree composites n such that (n,2*3) = 1 and prime p|n ==> p-4|n-4.

1705, 7015, 31369, 53599, 77809, 215635, 244885, 248239, 346801, 568879, 662935, 898105, 2151769, 2240515, 2782579, 9480829, 10665265, 11219485, 13644085, 13929205, 16549579, 17782879, 21592289, 29354329, 30075565, 35448439, 39792379

Offset

1,1

Comments

If multiples of 2 and 3 are not excluded, then terms like 6, 10, 15, 30, 70, 130, 165,... belong to the sequence. - Giovanni Resta, May 21 2013

Links

Giovanni Resta, Table of n, a(n) for n = 1..372 (terms < 10^12)

Index entries for sequences related to Carmichael numbers.

Mathematica

qcm[n_, d_] := Block[{p, e}, {p, e} = Transpose@FactorInteger@n; Length[p] > 1 && Max[e] == 1 && d < Min[p] && And @@ IntegerQ /@ ((n - d)/(p - d))]; Select[Range[10^6], qcm[#, 4] &] (* Giovanni Resta, May 21 2013 *)

Crossrefs

Sequence in context: A345506 A345782 A157287 * A222553 A345516 A345769

Adjacent sequences: A029556 A029557 A029558 * A029560 A029561 A029562

Keyword

nonn

Author

David W. Wilson

Status

approved