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 A014913 #40 Jun 30 2025 16:35:37
%S A014913 1,26,627,15052,361253,8670078,208081879,4993965104,119855162505,
%T A014913 2876523900130,69036573603131,1656877766475156,39765066395403757,
%U A014913 954361593489690182,22904678243752564383,549712277850061545208,13193094668401477085009,316634272041635450040234
%N A014913 a(1)=1, a(n) = 24*a(n-1) + n.
%H A014913 Vincenzo Librandi, <a href="/A014913/b014913.txt">Table of n, a(n) for n = 1..200</a>
%H A014913 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (26,-49,24).
%F A014913 a(1)=1, a(2)=26, a(3)=627, a(n) = 26*a(n-1) - 49*a(n-2) + 24*a(n-3). - _Vincenzo Librandi_, Oct 19 2012
%F A014913 From _Elmo R. Oliveira_, Mar 30 2025: (Start)
%F A014913 G.f.: x/((1-24*x)*(x-1)^2).
%F A014913 E.g.f.: exp(x)*(24*exp(23*x) - 23*x - 24)/529.
%F A014913 a(n) = (24^(n+1) - 23*n - 24)/529. (End)
%t A014913 LinearRecurrence[{26, -49, 24}, {1, 26, 627}, 20] (* _Vincenzo Librandi_, Oct 19 2012 *)
%t A014913 nxt[{n_,a_}]:={n+1,24a+n+1}; NestList[nxt,{1,1},20][[;;,2]] (* _Harvey P. Dale_, Jun 30 2025 *)
%o A014913 (Magma) I:=[1, 26, 627]; [n le 3 select I[n] else 26*Self(n-1) - 49*Self(n-2) + 24*Self(n-3): n in [1..20]]; // _Vincenzo Librandi_, Oct 19 2012
%Y A014913 Row n=24 of A126885.
%K A014913 nonn,easy
%O A014913 1,2
%A A014913 _N. J. A. Sloane_, _Olivier Gérard_