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A162310 The count of lesser-twin-primes smaller than the n-th isolated prime. 0

%I

%S 0,4,5,6,6,7,8,8,8,8,10,10,10,12,12,12,12,15,15,16,17,17,17,18,19,19,

%T 20,20,20,21,21,21,21,21,21,21,21,21,21,23,23,23,23,24,24,24,24,24,24,

%U 24,25,25,25,25,26,26,26,27,27,28,29,29,30,30,30,30,30,30,30,30,30,30

%N The count of lesser-twin-primes smaller than the n-th isolated prime.

%C The count of members of A001359 smaller than A007510(n).

%e a(1)=0 because there is no twin prime smaller than 2.

%e a(2)= 4 counts the numbers 3, 5, 11, and 17 all smaller than 23.

%e a(3) = 5 counts the numbers 3, 5, 11, 17, and 29 all smaller than 37.

%Y Cf. A000040, A141468, A073425.

%K nonn

%O 1,2

%A _Juri-Stepan Gerasimov_, Jul 01 2009

%E Entried checked by _R. J. Mathar_, Sep 23 2009

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Last modified February 28 01:49 EST 2020. Contains 332319 sequences. (Running on oeis4.)