A102656 Numbers k such that 11*k + 1 is prime.

2, 6, 8, 18, 30, 32, 36, 38, 42, 56, 60, 62, 66, 78, 80, 86, 90, 92, 102, 116, 120, 128, 132, 146, 162, 170, 182, 188, 192, 198, 206, 210, 212, 216, 218, 230, 242, 246, 248, 260, 266, 270, 276, 288, 290, 296, 300, 302, 308, 312, 318, 330, 336, 338, 350, 356, 366

Offset: 1

Author

Parthasarathy Nambi, Feb 02 2005

Keywords

• nonn

Examples

			At n=2, 11*2 + 1 = 23 (prime).
At n=60, 11*60 + 1 = 661 (prime).
At n=120, 11*120 + 1 = 1321 (prime).
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A141849, A215667.

Programs

GAP

Filtered([1..380], n-> IsPrime(11*n+1)); # G. C. Greubel, Apr 03 2019

Magma

[n: n in [1..380] | IsPrime(11*n+1)]; // G. C. Greubel, Apr 03 2019

Maple

select(t -> isprime(11*t+1), [seq(i,i=2..1000,2)]); # Robert Israel, Apr 03 2019

Mathematica

Select[ Range[2, 367, 2], PrimeQ[11# + 1] &] (* Robert G. Wilson v, Feb 04 2005 *)

PARI

is(n)=isprime(11*n+1) \\ Charles R Greathouse IV, Jun 06 2017

Sage

[n for n in (1..380) if is_prime(11*n+1)] # G. C. Greubel, Apr 03 2019

Formula

a(n) = (A141849(n) -1)/11 = 2*A215667(n). - Robert Israel, Apr 03 2019

Extensions

More terms from Robert G. Wilson v, Feb 04 2005