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 A121050 #7 May 15 2023 15:42:33
%S A121050 0,0,0,0,0,1,5,18,62,226,892,3835,17910,90401,490421,2844970,17570207,
%T A121050 115078228,796630963,5811215750,44551231383,358087648032,
%U A121050 3010990488143,26433752431402,241852566790848,2302304545944415,22768248457537798,233580248716343376
%N A121050 Partial sums of floor(n!/e^n).
%F A121050 a(n) = Sum_{i=1..n} floor(i!/exp(i)).
%t A121050 Accumulate[Table[Floor[n!/Exp[n]],{n,30}]] (* _Harvey P. Dale_, Aug 25 2016 *)
%Y A121050 Cf. A000142, A055775.
%K A121050 easy,nonn
%O A121050 1,7
%A A121050 _Jonathan Vos Post_, Aug 08 2006
%E A121050 Corrected by and incorrect examples removed by _Harvey P. Dale_, Aug 25 2016