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.

A206279 Smallest of three consecutive primes whose sum is a square.

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%I A206279 #18 Sep 18 2022 11:13:53
%S A206279 13,37,277,313,613,7591,8209,12157,14557,15679,16267,23053,32233,
%T A206279 42953,44887,55213,81013,94687,105649,106397,135241,203317,221401,
%U A206279 225769,235747,245941,258707,287671,306541,331333,342049,346111,347443,393853,479191,488827
%N A206279 Smallest of three consecutive primes whose sum is a square.
%H A206279 Charles R Greathouse IV, <a href="/A206279/b206279.txt">Table of n, a(n) for n = 1..10000</a>
%F A206279 a(n) = A000040(A076305(n)). - _Zak Seidov_, Apr 07 2017
%e A206279 a(4) = 313. The next two primes are 317 and 331, and 313 + 317 + 331 = 961 = 31^2.
%t A206279 Transpose[Select[Partition[Prime[Range[50000]],3,1],IntegerQ[ Sqrt[ Total[#]]]&]][[1]]
%o A206279 (PARI) p=2;q=3;forprime(r=5,1e9,if(issquare(p+q+r),print1(p", "));p=q;q=r) \\ _Charles R Greathouse IV_, Aug 28 2013
%Y A206279 Cf. A000040, A061275, A076304, A076305, A206280, A206281.
%K A206279 nonn
%O A206279 1,1
%A A206279 _Harvey P. Dale_, Feb 05 2012