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 A090561 #5 Dec 05 2013 19:56:38 %S A090561 1,4,64,81,16807,1000000,10000000,100000000,1000000000,10000000000, %T A090561 100000000000,1000000000000,10000000000000,100000000000000, %U A090561 1000000000000000,10000000000000000,100000000000000000 %N A090561 Least n-th power that begins with k^(n-1) for some k > 1. %C A090561 a(n) = 10^n for 6 <= n <= 500 (I haven't checked past 500.) - _David Wasserman_, Jan 05 2006 %e A090561 a(1) = 1 because 1 begins with 2^0. a(5) = 16807 because 16807 begins with 2^4. %Y A090561 Cf. A090568. %Y A090561 Cf. A067442. %K A090561 base,nonn %O A090561 1,2 %A A090561 _Amarnath Murthy_, Dec 11 2003 %E A090561 Corrected and extended by _David Wasserman_, Jan 05 2006