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A326586
Odd numbers which do not satisfy Korselt's criterion, complement of A324050.
0
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
1,1
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.
FORMULA
isA326586(n) = true if n != 1 and not isEven(n) and not isPrime(n) and not isCarmichael(n).
MATHEMATICA
Select[Range[3, 205, 2], CompositeQ[#] && Mod[#, CarmichaelLambda[#]] != 1&] (* Jean-François Alcover, Oct 16 2019 *)
CROSSREFS
Sequence in context: A039769 A270574 A071904 * A014076 A067800 A155474
KEYWORD
nonn
AUTHOR
Peter Luschny, Jul 21 2019
STATUS
approved