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 A097642 #10 Jul 16 2021 11:12:43
%S A097642 3,115,6576,80855
%N A097642 Numbers k such that k = (d_1! + d_2! + ... + d_k!) - (d_1 + d_2 + ... + d_k) where d_1 d_2 ... d_k is the decimal expansion of k.
%e A097642 80855 is in the sequence because 80855 = (8! + 0! + 8! + 5! + 5!) - (8 + 0 + 8 + 5 + 5).
%t A097642 okQ[n_]:=Module[{idn=IntegerDigits[n]},n==Total[idn!]-Total[idn]]; Select[Range[81000],okQ] (* _Harvey P. Dale_, Aug 26 2011 *)
%Y A097642 Cf. A097643.
%K A097642 base,fini,full,nice,nonn
%O A097642 1,1
%A A097642 _Farideh Firoozbakht_, Aug 22 2004