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 A109016 #5 Jul 13 2023 19:58:03
%S A109016 1,11,22,36,424,5120,6720,75040,840320,9362880,102,112,123,137,1425,
%T A109016 15121,16721,175041,1840321,19362881,203,213,224,238,2426,25122,26722,
%U A109016 275042,2840322,29362882,307,317,328,3312,3430,35126,36726,375046
%N A109016 Concatenate n and the sum of factorials of the digits of n.
%e A109016 a(16)=16721 because 1!+6! = 721.
%t A109016 Table[FromDigits[Join[IntegerDigits[n],IntegerDigits[Total[IntegerDigits[n]!]]]],{n,0,40}] (* _Harvey P. Dale_, Jul 13 2023 *)
%Y A109016 Cf. A061602.
%K A109016 base,easy,nonn
%O A109016 0,2
%A A109016 _Jason Earls_, Jun 16 2005