1,1

Table of n, a(n) for n=1..54.

(PARI) isok(k) = (prime(k) + prime(k+4)) == (prime(k+1) + prime(k+3)); \\ Michel Marcus, Sep 30 2013

Sequence in context: A303741 A085303 A304799 * A047524 A190447 A190375

Adjacent sequences: A022883 A022884 A022885 * A022887 A022888 A022889

nonn

Clark Kimberling

Corrected by R. J. Mathar, Aug 06 2015

approved