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 A269221 #12 Dec 19 2021 13:49:18
%S A269221 1,1,2,6,24,120,720,5040,40320,362880,1,2,6,24,120,720,5040,40320,
%T A269221 362880,3628800,2,6,24,120,720,5040,40320,362880,3628800,39916800,6,
%U A269221 24,120,720,5040,40320,362880,3628800,39916800,479001600,24,120,720,5040
%N A269221 Factorial of the sum of decimal digits of n.
%C A269221 Sequence A093659 is the binary (base 2) version.
%H A269221 Harvey P. Dale, <a href="/A269221/b269221.txt">Table of n, a(n) for n = 0..1000</a>
%F A269221 a(n) = A000142(A007953(n)).
%t A269221 Table[Total[IntegerDigits[n]]!,{n,0,50}] (* _Harvey P. Dale_, Dec 19 2021 *)
%o A269221 (PARI) A269221(n)=sumdigits(n)!
%Y A269221 Cf. A000142, A007953, A113588, A166350, A093659.
%K A269221 nonn,base
%O A269221 0,3
%A A269221 _M. F. Hasler_, Mar 15 2016