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 A018859 #16 Jan 29 2017 08:53:10 %S A018859 1,256,302231454903657293676544,4,5070602400912917605986812821504,64, %T A018859 70368744177664,81129638414606681695789005144064, %U A018859 91343852333181432387730302044767688728495783936,1024,1125899906842624 %N A018859 Smallest power of 4 that begins with n. %H A018859 Seiichi Manyama, <a href="/A018859/b018859.txt">Table of n, a(n) for n = 1..490</a> %F A018859 a(n) = 4^A018860(n). - _Michel Marcus_, Feb 24 2016 %F A018859 a(4^n) = 4^n for n >= 0. - _Seiichi Manyama_, Jan 29 2017 %Y A018859 Cf. A018802 (k=2), A018857 (k=3), this sequence (k=4), A018861 (k=5), A018863 (k=6), A018865 (k=7), A018867 (k=8), A018869 (k=9). %K A018859 nonn,base %O A018859 1,2 %A A018859 _David W. Wilson_