%N a(n) = A056171(k) - m, where k=prime(n) and m is the Ramanujan prime index to the greatest Ramanujan prime R(m) <= k.
%C a(n)=0 corresponds to the Ramanujan prime R_m = A104272(m) = A056171(k).
%F a(n) = A056171(k) - m, where k=prime(n) and m is the Ramanujan prime index to the greatest Ramanujan prime R_m = A104272(m) <= k.
%e For prime(30)=113, A056171(113) = 14, 107 is R_12 and 127 is R_13, so 14 -12 = 2 (first occurrence).
%o (PARI) \\RR[x] is a list of Ramanujan primes, A104272.
%o print1(s-primepi(floor(p/2))-n,", ");
%Y Cf. A056171, A104272.
%A _John W. Nicholson_, Jan 01 2017