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 A067493 #8 Oct 22 2018 12:40:54 %S A067493 1,16807,117649,1977326743,13841287201,1628413597910449, %T A067493 11398895185373143,191581231380566414401,1341068619663964900807, %U A067493 157775382034845806615042743,1104427674243920646305299201 %N A067493 Powers of 7 with initial digit 1. %H A067493 Muniru A Asiru, <a href="/A067493/b067493.txt">Table of n, a(n) for n = 1..357</a> %o A067493 (GAP) Filtered(List([0..40],n->7^n),i->ListOfDigits(i)[1]=1); # _Muniru A Asiru_, Oct 22 2018 %Y A067493 Cf. A067480, A067481, A067482, A067483, A067484, A067485, A067486, A067487, A067488, A067489, A067490, A067491, A067492. %K A067493 base,easy,nonn %O A067493 1,2 %A A067493 _Amarnath Murthy_, Feb 09 2002 %E A067493 Offset 1 by _Michel Marcus_, Oct 19 2018