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 A237604 #16 Jun 26 2022 03:08:02 %S A237604 93,237,245,453,469,645,741,765,1101,1133,1245,1253,1533,1573,2037, %T A237604 2045,2061,2085,2429,2613,2669,3045,3069,3261,3325,3981,3997,4005, %U A237604 4053,4245,4277,4773,4853,5637,5645,5685,5725,5957,5973,6573,6597,6669,7245,7293,7581,7685,8309 %N A237604 Numbers of form D^2 + 4d, with D odd, d divides D, and 1 < d < D. %C A237604 The period of the continued fraction expansion of sqrt(a(n)) = A003285(a(n)) is 10, so the a(n) are a subset of A020349. The periodic part of the continued fraction of sqrt(a(n)) is (D-d)/(2d),1,1,(D-1)/2,2D/d,(D-1)/2,1,1,(D-d)/(2d),2D. See the Bernstein paper. %C A237604 a(n) seems to be always congruent 5 (mod 8). %H A237604 Leon Bernstein, <a href="http://scholar.google.de/scholar?cluster=3688217905613415587">Fundamental units and cycles in the period of real quadratic number fields</a>, I. Pacific J. Math 63 (1976): 37-61. %o A237604 (PARI) list(n)=for(i=1,n,D=2*i+1;fordiv(D,d,if(d>1&&d<D,print1(D^2+4*d,",")))) %Y A237604 Cf. A003285, A020349. %K A237604 nonn %O A237604 1,1 %A A237604 _Ralf Stephan_, Feb 10 2014