A174184 Prime(n)+even nonprime(n) is prime.

1, 2, 3, 7, 9, 11, 12, 13, 14, 18, 24, 27, 28, 29, 30, 36, 38, 43, 44, 53, 54, 55, 57, 60, 63, 64, 65, 66, 72, 74, 80, 84, 90, 93, 102, 103, 108, 110, 111, 117, 118, 125, 126, 135, 138, 141, 143, 148, 150, 155, 156, 162, 165, 171, 174, 180, 183, 186, 188, 190, 198

Offset: 1

Author

Juri-Stepan Gerasimov, Mar 11 2010

Keywords

• nonn

Comments

Unit together with prime(n)+s*n is prime, s=2.

Examples

			1 is in the sequence because A000040(1) + A163300(1) = 2 (1st prime) + 0 (1st even nonprime) is prime;
2 is in the sequence because A000040(2) + A163300(2) = 3 (2nd prime) + 4 (2nd even nonprime) is prime.
		

Crossrefs

Cf. A000040, A076297, A163300.

Programs

Maple

From R. J. Mathar, Apr 20 2010: (Start)
A163300 := proc(n) option remember ; if n = 1 then 0; else for a from procname(n-1)+2 by 2 do if not isprime(a) then return a ; end if; end do; end if; end proc:
for n from 1 to 200 do if isprime( ithprime(n) + A163300(n)) then printf("%d,",n) ; end if; end do: (End)

Formula

a(n+1)=A076297(n).

Extensions

Entries checked by R. J. Mathar, Apr 20 2010