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.

A085317 Primes which are the sum of three nonzero squares.

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%I A085317 #27 Jun 21 2022 14:05:38
%S A085317 3,11,17,19,29,41,43,53,59,61,67,73,83,89,97,101,107,109,113,131,137,
%T A085317 139,149,157,163,173,179,181,193,197,211,227,229,233,241,251,257,269,
%U A085317 277,281,283,293,307,313,317,331,337,347,349,353,373,379,389,397,401
%N A085317 Primes which are the sum of three nonzero squares.
%C A085317 This sequence consists of the primes p (not 5, 13, or 37) such that p == 1, 3 or 5 (mod 8). The density of these primes is 0.75. - _T. D. Noe_, May 21 2004
%C A085317 Primes of the form a^2 + b^2 + c^2 with 1 <= a <= b <= c. - _Zak Seidov_, Nov 08 2013
%H A085317 Amiram Eldar, <a href="/A085317/b085317.txt">Table of n, a(n) for n = 1..10000</a>
%e A085317 101 is a term since 101 = 64 + 36 + 1 = 8^2 + 6^2 + 1^2.
%t A085317 lst={}; lim=32; Do[n=a^2+b^2+c^2; If[n<lim^2 && PrimeQ[n], lst=Union[lst, {n}]], {a, lim}, {b, a, Sqrt[lim^2-a^2]}, {c, b, Sqrt[lim^2-a^2-b^2]}]; lst
%t A085317 With[{nn=30},Select[Union[Total/@Tuples[Range[nn]^2,3]],PrimeQ[#]&& #<= nn^2+2&]] (* _Harvey P. Dale_, Jun 18 2022 *)
%Y A085317 Cf. A000408.
%Y A085317 Cf. A094712 (primes that are not the sum of three positive squares).
%Y A085317 Cf. A094713 (number of ways that prime(n) can be represented as a^2+b^2+c^2 with a >= b >= c > 0).
%K A085317 nonn
%O A085317 1,1
%A A085317 _Labos Elemer_, Jul 01 2003