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.

A087293 Numbers k such that ((prime(k)*prime(k+1))^2 + 1)/2 is prime.

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%I A087293 #11 Mar 18 2022 15:29:25
%S A087293 2,3,6,14,27,30,35,37,44,55,101,106,118,127,137,140,154,172,184,233,
%T A087293 248,256,260,289,383,389,425,461,463,485,500,503,513,552,584,610,617,
%U A087293 630,642,696,706,714,737,746,819,884,926,952,964,978,1004,1008,1019,1027
%N A087293 Numbers k such that ((prime(k)*prime(k+1))^2 + 1)/2 is prime.
%C A087293 Resulting primes are in A087294.
%H A087293 Harvey P. Dale, <a href="/A087293/b087293.txt">Table of n, a(n) for n = 1..1000</a>
%e A087293 2 is in the sequence because ((prime(2)*prime(3))^2 + 1)/2 = ((3*5)^2 + 1)/2 = 113 is prime.
%t A087293 Select[Range[1100],PrimeQ[((Prime[#]Prime[#+1])^2+1)/2]&] (* _Harvey P. Dale_, Mar 18 2022 *)
%Y A087293 Cf. A086893, A087294.
%K A087293 nonn
%O A087293 1,1
%A A087293 _Ray Chandler_, Aug 31 2003
%E A087293 Offset changed to 1 by _Jinyuan Wang_, Aug 06 2021