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 A353087 #18 Apr 23 2022 01:40:53 %S A353087 23,34,40,55,59,67,75,81,90,90,97,108,118,123,131,144,147,147,147,157, %T A353087 157,182,186,186,186,189,203,204,206,206,209,232,232,236,236,237,237, %U A353087 245,257,257,265,278,282,282,282,282,282,290,307,307,318,318,318,318,341 %N A353087 Smallest integer k such that k! contains at least n copies of each decimal digit. %H A353087 Alois P. Heinz, <a href="/A353087/b353087.txt">Table of n, a(n) for n = 1..5000</a> %e A353087 23! = 25852016738884976640000 is the smallest factorial containing at least one copy of each decimal digit. Thus a(1) = 23. %p A353087 a:= proc(n) option remember; local k; for k from a(n-1) %p A353087 while min((p-> seq(coeff(p, x, j), j=0..9))(add( %p A353087 x^i, i=convert(k!, base, 10))))<n do od; k %p A353087 end: a(0):=0: %p A353087 seq(a(n), n=1..100); %o A353087 (Python) %o A353087 def A353087(n): %o A353087 k, m, r = 1, 1, 10**(10*n-1) %o A353087 while m < r: %o A353087 k += 1 %o A353087 m *= k %o A353087 s = str(m) %o A353087 while any(s.count(d) < n for d in '0123456789'): %o A353087 k += 1 %o A353087 m *= k %o A353087 s = str(m) %o A353087 return k # _Chai Wah Wu_, Apr 22 2022 %Y A353087 Cf. A000142, A352040. %K A353087 nonn,base %O A353087 1,1 %A A353087 _Alois P. Heinz_, Apr 22 2022