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 A110072 #18 Feb 20 2024 00:44:46
%S A110072 1,163800,1547520,81254720
%N A110072 Numbers k such that k = sigma(d_1!!*d_2!!*...*d_j!!) where d_1 d_2 ... d_j is the decimal expansion of k.
%C A110072 No more terms up to 10^25. It is very probable that there is no greater term. - _Robert Gerbicz_, May 09 2008
%C A110072 No other terms below 10^45. - _Max Alekseyev_, Feb 19 2024
%e A110072 81254720 is a term because 81254720 = sigma(8!!*1!!*2!!*5!!*4!!*7!!*2!!*0!!).
%t A110072 Do[h = IntegerDigits[n]; l = Length[h]; If[n == DivisorSigma[1, Product[h[[k]]!!, {k, l}]], Print[n]], {n, 0, 100000000}]
%Y A110072 Cf. A000203, A097655, A110070, A110071.
%K A110072 base,more,nonn
%O A110072 1,2
%A A110072 _Farideh Firoozbakht_, Jul 22 2005