A104491 - OEIS

%I #4 Mar 30 2012 18:40:27

%S 2,5,13,19,23,37,67,71,83,107,109,113,139,157,173,199,271

%N Prime numbers n for which the square excess of the n-th prime is prime.

%F n such that A102821(n) is prime. n such that A053186(A000040(n)) is an element of A000040.

%e 199 is an element of this sequence because 199 is prime and the 199th prime is 1217 and 1217 - 34^2 = 61 and 61 is prime, while 1217 - 35^2 = -8.

%Y Cf. A000040, A053186, A102821.

%K easy,nonn

%O 1,1

%A _Jonathan Vos Post_, Mar 10 2005