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 A045511 #17 Jul 19 2020 02:13:17 %S A045511 362880,3628800,39916800,355687428096000, %T A045511 304888344611713860501504000000, %U A045511 371993326789901217467999448150835200000000 %N A045511 Factorials having initial digit '3'. %C A045511 Benford's law shows that this sequence will contain about (log 4 - log 3)/log 10 =~ 12% of factorials. [_Charles R Greathouse IV_, Nov 13 2010] %H A045511 <a href="/index/Be#Benford">Index entries for sequences related to Benford's law</a> %F A045511 a(n) = A000142(A045522(n)). - _Amiram Eldar_, Jul 19 2020 %t A045511 Select[Range[100]!,First[IntegerDigits[#]]==3&] (* _Harvey P. Dale_, Jun 16 2016 *) %Y A045511 For factorials with initial digit d (1 <= d <= 9) see A045509, A045510, A045511, A045516, A045517, A045518, A282021, A045519; A045520, A045521, A045522, A045523, A045524, A045525, A045526, A045527, A045528, A045529. %Y A045511 Cf. A000142. %K A045511 nonn,base %O A045511 1,1 %A A045511 _Jeff Burch_