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 A155455 #28 Jan 29 2024 08:54:32
%S A155455 0,1,5,41,285,2081,14965,108121,780045,5630161,40631525,293240201,
%T A155455 2116305405,15273370241,110227737685,795512612281,5741206864365,
%U A155455 41434236118321,299030490421445,2158100230000361,15574988996744925,112404548663730401,811222567266570805
%N A155455 a(n) = 5*a(n-1)+16*a(n-2), n>1 ; a(0)=0, a(1)=1.
%C A155455 a(n+1) for n >= 0 is the number of compositions (ordered partitions) of n into parts 1 of 5 sorts and parts 2 of 16 sorts. - _Joerg Arndt_, Jan 29 2024
%H A155455 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,16).
%F A155455 G.f.: x/(1-5*x-16*x^2).
%t A155455 LinearRecurrence[{5, 16}, {0, 1}, 25] (* _Paolo Xausa_, Jan 29 2024 *)
%Y A155455 Cf. A015568 (binomial transform).
%K A155455 nonn,easy
%O A155455 0,3
%A A155455 _Philippe Deléham_, Jan 22 2009
%E A155455 Regularized: a(0) set to 0. - _R. J. Mathar_, Apr 01 2011
%E A155455 a(21)-a(22) from _Paolo Xausa_, Jan 29 2024