A184899 n such that the n-th centered 12-gonal number is prime. Indices of prime star numbers.

2, 3, 4, 6, 8, 9, 10, 11, 13, 14, 19, 20, 21, 23, 24, 31, 32, 33, 34, 36, 37, 39, 42, 43, 44, 46, 47, 48, 52, 56, 59, 61, 66, 68, 74, 75, 78, 79, 85, 87, 89, 94, 96, 98, 101, 102, 105, 107, 108, 110, 113, 118, 121, 124, 125, 127, 130, 131, 133, 135, 136, 138

Offset: 1

Author

Jonathan Vos Post, Feb 01 2011

Keywords

• nonn
• easy

Comments

For n > 3, A003154(a(n)) = A057199(2*a(n)-2). - Chai Wah Wu, Sep 17 2019

Examples

			98 is in the sequence because 6*98^2 - 6*98 + 1 = 57037 is prime.
		

Links

• Zak Seidov, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A083577, A000040, A003154, A057199.

Programs

Mathematica

Select[Range[140],PrimeQ[6#^2-6#+1]&]  (* Harvey P. Dale, Feb 16 2011 *)

Formula

{n: 6*n^2 - 6*n + 1 is prime} = {n: A003154(n) is in A000040}.