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 A025648 #7 Jul 06 2025 12:42:09 %S A025648 0,1,0,2,1,0,3,2,1,4,0,3,2,5,1,4,0,3,6,2,5,1,4,7,0,3,6,2,5,8,1,4,7,0, %T A025648 3,6,9,2,5,8,1,4,7,0,10,3,6,9,2,5,8,1,11,4,7,0,10,3,6,9,2,12,5,8,1,11, %U A025648 4,7,0,10,3,13,6,9,2,12,5,8,1,11,4,14,7,0,10,3,13,6,9,2,12,5,15,8,1,11,4,14,7 %N A025648 Exponent of 4 (value of i) in n-th number of form 4^i*7^j. %Y A025648 Cf. A025619. %K A025648 nonn %O A025648 1,4 %A A025648 _David W. Wilson_