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 A197127 #14 Mar 31 2012 10:22:18
%S A197127 6,14,22,30,34,38,42,46,54,56,62,66,69,70,78,86,87,93,94,102,110,114,
%T A197127 115,118,126,130,132,134,138,142,146,150,154,155,156,158,159,166,174,
%U A197127 177,178,182,183,184,185,186,190,194,198,206,210,214,220,222,228,230
%N A197127 Nonsquare positive integers n such that the fundamental unit of quadratic field Q(sqrt(d))is singular.
%C A197127 x^2+n*y^2=(+/-)2^s where s is 0 or 1.
%C A197127 Definition: Unity is singular when GCD[n,y]<>1.
%e A197127 a(1)=6 because unity of quadratic field Q(6) is 5+2*Sqrt[6] and GCD[2,6]=2 <>1.
%t A197127 cr = {}; Do[If[IntegerQ[Sqrt[n]], , kk = NumberFieldFundamentalUnits[Sqrt[n]]; d1 = kk[[1]][[2]][[1]]; d2 = kk[[1]][[1]] kk[[1]][[2]][[2]]; d4 = Numerator[d2/Sqrt[n]]; If[GCD[d4, n] == 1, , AppendTo[cr, n]]], {n, 2, 330}]; cr (*Artur Jasinski*)
%Y A197127 Cf. A087643, A172000, A194366, A197115, A197128.
%K A197127 nonn
%O A197127 1,1
%A A197127 _Artur Jasinski_, Oct 10 2011