A224467 Numbers n such that 27*n+1 is prime.

4, 6, 10, 14, 16, 18, 20, 28, 30, 34, 48, 54, 58, 60, 66, 74, 76, 80, 84, 88, 94, 96, 98, 108, 110, 114, 118, 128, 130, 136, 138, 144, 146, 150, 154, 166, 170, 180, 184, 186, 188, 198, 206, 214, 230, 236, 238, 240, 258, 264, 268, 278, 280, 284, 286, 296, 300

Offset: 1

Author

K. D. Bajpai, Jul 20 2013

Keywords

• nonn
• easy

Examples

			27*6 + 1 = 163 which is prime. Hence 6 is in the sequence.
		

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..5736

Crossrefs

Cf. A005123, A024906.

Programs

Maple

isA224467 := proc(n)
    isprime(27*n+1) ;
end proc:
for n from 1 to 300 do
    if isA224467(n) then
        printf("%d,",n) ;
    end if;
end do: # R. J. Mathar, Jul 20 2013

Mathematica

Select[Range[300],PrimeQ[27#+1]&] (* Harvey P. Dale, Apr 14 2017 *)

PARI

is(n)=isprime(27*n+1) \\ Charles R Greathouse IV, Jun 06 2017