The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.

a(3) = nextprime(3) - prevprime(3) = 5 - 2 = 3: This shows that here the variants 2 (A151800 and A151799) of the nextprime and precprime functions are used, rather than the variants A007918 and A007917. - M. F. Hasler, Sep 09 2015

MAPLE

[ seq(nextprime(i)-prevprime(i), i=3..100) ];

PROG

(PARI) A013633(n)=nextprime(n+1)-precprime(n-1) \\ M. F. Hasler, Sep 09 2015