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 A137582 #11 Jun 28 2023 08:19:42 %S A137582 0,1,2,3,4,5,6,9,10,11,14,31,40 %N A137582 Numbers having no inner zeros in decimal representation of their factorial. %C A137582 Conjecture: the sequence is finite. %H A137582 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>. %F A137582 A137581(a(n)) = 0. %e A137582 A000142(a(10)) = 11! = 399168*10^2; %e A137582 A000142(a(11)) = 14! = 871782912*10^2; %e A137582 A000142(a(12)) = 31! = 822283865417792281772556288*10^7. %o A137582 (PARI) isok(k) = my(f=k!); while(!(f % 10), f \= 10); #select(x->(x == 0), digits(f)) == 0; \\ _Michel Marcus_, Jun 28 2023 %Y A137582 Cf. A000142, A027869, A027868, A137581. %K A137582 nonn,base,more %O A137582 1,3 %A A137582 _Reinhard Zumkeller_, Jan 27 2008