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.
%I A046712 #48 Jul 02 2025 16:01:57
%S A046712 6,14,21,22,30,33,38,42,46,54,57,62,66,69,70,77,78,86,93,94,102,105,
%T A046712 110,114,118,126,129,133,134,138,141,142,150,154,158,161,165,166,174,
%U A046712 177,182,186,189,190,198,201,206,209,210,213,214,217,222,230,237,238
%N A046712 From the Bruck-Ryser theorem: n == 1 or 2 (mod 4) which are not the sum of 2 squares.
%C A046712 Intersection of A022544 and A046712. - _Reinhard Zumkeller_, Aug 16 2011
%D A046712 M. Hall, Jr., Combinatorial Theory, Wiley, New York, 1986, see Theorem 12.3.2.
%H A046712 Reinhard Zumkeller, <a href="/A046712/b046712.txt">Table of n, a(n) for n = 1..10000</a>
%H A046712 R. H. Bruck and H. J. Ryser, <a href="http://dx.doi.org/10.4153/CJM-1949-009-2">The nonexistence of certain projective planes</a>, Canad. J. Math., 1 (1949), 88-93.
%H A046712 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Bruck-Ryser-ChowlaTheorem.html">Bruck-Ryser-Chowla Theorem</a>.
%H A046712 Wikipedia, <a href="http://en.wikipedia.org/wiki/Bruck-Ryser-Chowla_theorem">Bruck-Ryser-Chowla theorem</a>.
%H A046712 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>
%t A046712 Select[Range[240], (Mod[#, 4] == 1 || Mod[#, 4] == 2) && PowersRepresentations[#, 2, 2] == {} & ] (* _Jean-François Alcover_, Aug 30 2011 *)
%t A046712 Select[Range[250],MemberQ[{1,2},Mod[#,4]]&&SquaresR[2,#]==0&] (* _Harvey P. Dale_, Apr 01 2015 *)
%o A046712 (Haskell)
%o A046712 a046712 n = a046712_list !! (n-1)
%o A046712 a046712_list = filter ((`elem` [1,2]) . (`mod` 4)) a022544_list
%o A046712 -- _Reinhard Zumkeller_, Aug 16 2011
%K A046712 nonn,easy,nice
%O A046712 1,1
%A A046712 _N. J. A. Sloane_
%E A046712 More terms from _James Sellers_