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 A280379 a(n) = A056171(k) - m, where k=prime(n) and m is the Ramanujan prime index to the greatest Ramanujan prime R(m) <= k. 1

%I

%S 0,1,1,1,0,1,0,1,1,0,1,1,0,1,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1,2,0,1,1,2,

%T 0,0,1,1,0,1,0,0,1,2,2,3,2,1,0,0,0,0,0,1,1,0,0,1,1,0,1,2,0,0,1,1,1,1,

%U 0,0,1,1,0,0,1,1,1,1,0

%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 {plimit=1.1*10^4;n=s=0;

%o forprime(p=2,plimit,

%o s++;

%o if(p==RR[n+1],n++);

%o print1(s-primepi(floor(p/2))-n,", ");

%o )

%o }

%Y Cf. A056171, A104272.

%K nonn

%O 1,30

%A _John W. Nicholson_, Jan 01 2017

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Last modified October 21 08:47 EDT 2019. Contains 328292 sequences. (Running on oeis4.)