A174185 - OEIS

%I #9 Feb 04 2019 02:08:37

%S 1,7,8,9,12,15,19,20,21,23,24,25,30,32,33,34,35,36,37,39,41,42,45,46,

%T 48,51,56,63,67,71,75,78,81,82,85,86,88,89,90,96,102,107,112,115,116,

%U 117,120,121,123,126,128,132,135,137,146,150,152,153,156,158,159,163,164

%N Numbers k such that the k-th prime minus the k-th even nonprime is prime.

%C Numbers k such that prime(k) - (even nonprime)(k) is prime.

%e 1 is a term because A000040(1) - A163300(1) = 2 (prime);

%e 7 is a term because A000040(7) - A163300(7) = 3 (prime).

%p 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:

%p for n from 1 to 300 do if isprime( ithprime(n) - A163300(n)) then printf("%d,",n) ; end if; end do: # _R. J. Mathar_, Apr 20 2010

%Y Cf. A000040, A163300.

%K nonn

%O 1,2

%A _Juri-Stepan Gerasimov_, Mar 11 2010

%E Corrected (11 replaced with 12) by _R. J. Mathar_, Apr 20 2010