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A171387 The characteristic function of primes > 3: 1 if n is prime such that neither prime+-1 is prime else 0. 2

%I #7 Oct 04 2017 14:03:27

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

%T 0,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,

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

%N The characteristic function of primes > 3: 1 if n is prime such that neither prime+-1 is prime else 0.

%H Antti Karttunen, <a href="/A171387/b171387.txt">Table of n, a(n) for n = 1..1001</a>

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%F A010051(n) = a(n) + A171386(n).

%F If n > 3, a(n) = A010051(n), otherwise a(n) = 0. - _Antti Karttunen_, Oct 04 2017

%Y Cf. A000007, A010051, A063524, A080545, A169546, A171386.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Dec 07 2009

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