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 A221707 #8 Aug 14 2020 13:55:43 %S A221707 2,4,8,12,16,20,25,29,34,39,44,49,55,60,65,71,82,88,94,105,111,117, %T A221707 123,136,142,148,154,167,173,180,186,193,199,206,212,219,225,232,239, %U A221707 252,259,266,279,286,293,300,307,314,321,328,335,342,349,356,363,370 %N A221707 Numbers n such that A216377(n) = 1. %H A221707 Alois P. Heinz, <a href="/A221707/b221707.txt">Table of n, a(n) for n = 1..1000</a> %t A221707 Select[Range[2,400],IntegerDigits[#!,#][[1]]==1&] (* _Harvey P. Dale_, Aug 14 2020 *) %Y A221707 Cf. A216377, A221708. %K A221707 nonn %O A221707 1,1 %A A221707 _N. J. A. Sloane_, Jan 25 2013 %E A221707 More terms from _Alois P. Heinz_, Jan 28 2013