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 A155652 #11 Jun 12 2015 15:26:55 %S A155652 1,4,46,514,5266,51274,484786,4503034,41367106,377342794,3426318226, %T A155652 31018262554,280252754146,2528805134314,22798428290866, %U A155652 205420947110074,1850199078944386,16660255040221834,149993075340330706 %N A155652 9^n-6^n+1. %H A155652 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (16,-69,54). %F A155652 G.f.: 1/(1-9*x)-1/(1-6*x)+1/(1-x). E.g.f.: e^(9*x)-e^(6*x)+e^x. %F A155652 a(n)=15*a(n-1)-54*a(n-2)+40 with a(0)=1, a(1)=4 - _Vincenzo Librandi_, Jul 21 2010 %o A155652 (PARI) a(n)=9^n-6^n+1^n \\ _Charles R Greathouse IV_, Jun 11 2015 %Y A155652 Cf. A155628, A155629, A155630, A155631, A155632, A155633, A155634, A155635, A155636, A155637, A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645, A155646, A155647, A155648, A155649, A155650, A155651. %K A155652 nonn,easy %O A155652 0,2 %A A155652 _Mohammad K. Azarian_, Jan 31 2009