A263028 Numbers n such that A002322(n) + 1 is a prime, where A002322 is Carmichael lambda.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78, 79, 80, 82, 83

Offset: 1

Author

Vincenzo Librandi, Oct 12 2015

Keywords

• nonn
• easy

Comments

Complement of A263029.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..39743

Crossrefs

Cf. A002322, A263027, A263029, A296077 (characteristic function).

Cf. also A039698.

Programs

Magma

[1] cat [n: n in [2..100] | IsPrime(CarmichaelLambda(n)+1)];

Mathematica

Select[Range[1, 100], PrimeQ[CarmichaelLambda[#] + 1] &]

PARI

for(n=1, 1e3, if(isprime((1 + lcm(znstar(n)[2]))), print1(n", "))) \\ Altug Alkan, Oct 12 2015

Extensions

More terms from Antti Karttunen, Dec 05 2017