A326586 Odd numbers which do not satisfy Korselt's criterion, complement of A324050.

9, 15, 21, 25, 27, 33, 35, 39, 45, 49, 51, 55, 57, 63, 65, 69, 75, 77, 81, 85, 87, 91, 93, 95, 99, 105, 111, 115, 117, 119, 121, 123, 125, 129, 133, 135, 141, 143, 145, 147, 153, 155, 159, 161, 165, 169, 171, 175, 177, 183, 185, 187, 189, 195, 201, 203, 205

Offset: 1

Author

Peter Luschny, Jul 21 2019

Keywords

• nonn

Comments

The first number k > 1 not in this sequence but in A014076 is 561, because for every p in {3, 11, 17}, which are the prime divisors of 561, p - 1 divides 560.

Crossrefs

Cf. A324050, A014076.

Programs

Mathematica

Select[Range[3, 205, 2], CompositeQ[#] && Mod[#, CarmichaelLambda[#]] != 1&] (* Jean-François Alcover, Oct 16 2019 *)

Formula

isA326586(n) = true if n != 1 and not isEven(n) and not isPrime(n) and not isCarmichael(n).