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 A054111 #9 Jun 13 2015 00:50:14 %S A054111 1,2,7,18,39,82,167,338,679,1362,2727,5458,10919,21842,43687,87378, %T A054111 174759,349522,699047,1398098,2796199,5592402,11184807,22369618, %U A054111 44739239,89478482,178956967,357913938,715827879,1431655762 %N A054111 Row sums of array T as in A054110. %H A054111 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2,1,-2) %F A054111 G.f.: [1+2x^2+4x^3]/[(1-x^2)(1-2x)]. - _Ralf Stephan_, Apr 03 2004 %F A054111 a(n+1) = 2^(n+4)/3 -7/2 +(-1)^n/6, n>0. - _R. J. Mathar_, May 20 2013 %K A054111 nonn %O A054111 0,2 %A A054111 _Clark Kimberling_