cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A167771 Twice-isolated primes: primes p such that neither p+-2 nor p+-4 is prime.

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%I A167771 #7 Sep 21 2016 16:40:20
%S A167771 2,53,89,157,173,211,251,257,263,293,331,337,359,367,373,389,409,449,
%T A167771 479,509,541,547,557,563,577,587,593,607,631,653,683,691,701,709,719,
%U A167771 727,733,751,787,797,839,919,929,947,953,977,983,991,997,1039,1069,1103
%N A167771 Twice-isolated primes: primes p such that neither p+-2 nor p+-4 is prime.
%C A167771 2 together with primes p with property that (p-previous prime)>=6 and (next prime-p)>=6.
%C A167771 By the finitude of the generalized Brun constants, this sequence includes almost all primes.
%H A167771 Harvey P. Dale, <a href="/A167771/b167771.txt">Table of n, a(n) for n = 1..1000</a>
%e A167771 a(1)=2 (-2,0,4,6 are nonprimes); a(2)=53 (49,51,55,57 are nonprimes).
%t A167771 Join[{2},Select[Prime[Range[200]],NoneTrue[#+{4,2,-2,-4},PrimeQ]&]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 21 2016 *)
%Y A167771 Cf. A007510, A137869.
%K A167771 nonn
%O A167771 1,1
%A A167771 _Juri-Stepan Gerasimov_, Nov 11 2009
%E A167771 Comment from _Charles R Greathouse IV_, Nov 12 2009