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a(n) is the number of primes q less than n-th prime p for which the Euclidean algorithm for p,q has exactly 3 nonzero remainders.
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%I #14 Aug 08 2021 08:38:27

%S 0,0,0,0,1,1,1,1,4,2,2,3,1,3,6,7,5,5,4,8,5,5,10,9,6,4,5,7,8,9,6,8,8,6,

%T 8,7,5,8,9,10,13,7,10,9,8,9,8,7,7,11,11,14,13,14,15,15,8,9,12,5,17,15,

%U 9,12,9,10,5,8,9,14,12,16,15,12,9,16,18,12,11

%N a(n) is the number of primes q less than n-th prime p for which the Euclidean algorithm for p,q has exactly 3 nonzero remainders.

%e For prime(9)=23, the primes counted are 5,13,17,19.

%Y Cf. A049848, A049850.

%K nonn

%O 1,9

%A _Clark Kimberling_

%E More terms from _Sean A. Irvine_, Aug 07 2021