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 A199774 #22 Jan 05 2016 19:00:33 %S A199774 0,3,5,32,203,333,2112,13395,21973,139360,883867,1449885,9195648, %T A199774 58321827,95670437,606773408,3848356715,6312798957,40037849280, %U A199774 253933221363,416549060725,2641891279072,16755744253243,27485925208893,174324786569472,1105625187492675 %N A199774 x-values in the solution to 17*x^2 + 16 = y^2. %C A199774 When are both n-1 and 17*n-1 perfect squares? This problem gives the equation 17*x^2+16=y^2. %H A199774 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,66,0,0,-1). %F A199774 a(n) = 66*a(n-3) - a(n-6), a(1)=0, a(2)=3, a(3)=5, a(4)=32, a(5)=203, a(6)=333. %F A199774 G.f.: x^2*(3*x^4+5*x^3+32*x^2+5*x+3) / (x^6-66*x^3+1). - _Colin Barker_, Sep 01 2013 %e A199774 a(7)=66*32-0=2112. %t A199774 LinearRecurrence[{0,0,66,0,0,-1}, {0,3,5,32,203,333}, 50] %o A199774 (PARI) Vec(x^2*(3*x^4+5*x^3+32*x^2+5*x+3)/(x^6-66*x^3+1) + O(x^100)) \\ _Colin Barker_, Sep 01 2013 %Y A199774 Cf. A199772, A199773, A199798. %K A199774 nonn,easy %O A199774 1,2 %A A199774 _Sture Sjöstedt_, Nov 10 2011 %E A199774 More terms from _T. D. Noe_, Nov 10 2011