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 A022312 #20 Aug 25 2017 23:35:00 %S A022312 0,7,8,16,25,42,68,111,180,292,473,766,1240,2007,3248,5256,8505,13762, %T A022312 22268,36031,58300,94332,152633,246966,399600,646567,1046168,1692736, %U A022312 2738905,4431642,7170548,11602191,18772740,30374932,49147673,79522606,128670280 %N A022312 a(n) = a(n-1) + a(n-2) + 1 for n>1, a(0)=0, a(1)=7. %H A022312 G. C. Greubel, <a href="/A022312/b022312.txt">Table of n, a(n) for n = 0..1000</a> %H A022312 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,-1) %F A022312 Equals A022098(n) - 1. %F A022312 G.f.: x*(7-6*x)/( (1-x)*(1-x-x^2) ). - _R. J. Mathar_, Apr 07 2011 %F A022312 a(n) = F(n+2) + 6*F(n) - 1, where F = A000045. - _G. C. Greubel_, Aug 25 2017 %t A022312 LinearRecurrence[{2, 0, -1}, {0, 7, 8}, 60] (* _Vladimir Joseph Stephan Orlovsky_, Feb 16 2012 *) %o A022312 (PARI) x='x+O('x^50); concat([0],Vec(x*(7-6*x)/( (1-x)*(1-x-x^2) ))) \\ _G. C. Greubel_, Aug 25 2017 %Y A022312 Cf. A000045. %K A022312 nonn,easy %O A022312 0,2 %A A022312 _N. J. A. Sloane_