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 A018876 #19 Jan 31 2017 10:05:13 %S A018876 0,1,3,12,9,34,13,5,7,37,10,38,2,28,76,55,4,15,21,11,8,3,58,42,22,114, %T A018876 16,6,116,84,117,44,85,119,23,12,167,45,234,63,88,17,33,46,89,24,173, %U A018876 9,174,65,47,91,34,127,66,92,128,248,48,129,67,18,13,181,35,351,131,49,183,95,255 %N A018876 a(n)^7 is smallest seventh power beginning with n. %H A018876 Seiichi Manyama, <a href="/A018876/b018876.txt">Table of n, a(n) for n = 0..10000</a> %F A018876 a(n^7) = n for n >= 0. - _Seiichi Manyama_, Jan 30 2017 %e A018876 a(2)=3, because 3^7=2187 is the first 7th power with the most significant digit 2; %e A018876 a(16)=4, because 4^7=16384 is the first 7th power whose two most significant digits are 16. %Y A018876 Cf. A018851 (k=2), A018852 (k=3), A018853 (k=4), A018872 (k=5), A018874 (k=6), this sequence (k=7), A018878 (k=8), A018880 (k=9), A018882 (k=10). %K A018876 nonn,base %O A018876 0,3 %A A018876 _David W. Wilson_ %E A018876 Added initial 0. - _Seiichi Manyama_, Jan 30 2017