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 A227191 #23 Apr 19 2025 19:36:10
%S A227191 0,1,2,2,3,5,6,7,8,8,9,10,11,12,13,12,13,15,16,17,18,16,17,23,24,25,
%T A227191 26,26,27,29,30,31,32,32,33,34,35,36,37,36,37,39,40,41,42,40,41,46,47,
%U A227191 48,49,48,49,52,53,54,55,54,55,56,57,58,59,56,57,60,61,62
%N A227191 a(n) = n minus (product of nonzero digits in factorial base representation of n).
%H A227191 Antti Karttunen, <a href="/A227191/b227191.txt">Table of n, a(n) for n = 1..5040</a>
%H A227191 <a href="/index/Fa#facbase">Index entries for sequences related to factorial base representation</a>.
%F A227191 a(n) = n - A227153(n).
%e A227191 22 has factorial expansion A007623(22) = "320", and multiplying the nonzero digits, we get 3*2 = 6, and 22-6 = 16, thus a(22)=16.
%t A227191 a[n_] := Module[{k = n, m = 2, r, p = 1}, While[{k, r} = QuotientRemainder[k, m]; k != 0|| r != 0, If[r > 0, p *= r]; m++]; n - p]; Array[a, 100] (* _Amiram Eldar_, Feb 14 2024 *)
%o A227191 (Scheme) (define (A227191 n) (- n (A227153 n)))
%Y A227191 Cf. A007623, A227153, A219651, A227190.
%K A227191 nonn,base
%O A227191 1,3
%A A227191 _Antti Karttunen_, Jul 04 2013