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 A025650 #14 Jul 09 2025 12:49:29
%S A025650 0,0,1,0,1,2,0,1,2,3,0,1,2,3,4,0,1,2,3,4,5,0,1,2,3,4,5,6,0,1,2,3,4,5,
%T A025650 6,0,7,1,2,3,4,5,6,0,7,1,8,2,3,4,5,6,0,7,1,8,2,9,3,4,5,6,0,7,1,8,2,9,
%U A025650 3,10,4,5,6,0,7,1,8,2,9,3,10,4,11,5,6,0,7,1,8,2,9,3,10,4,11,5,12,6,0,7,1,8,2,9
%N A025650 Exponent of 5 (value of j) in n-th number of form 4^i*5^j.
%H A025650 Amiram Eldar, <a href="/A025650/b025650.txt">Table of n, a(n) for n = 1..10000</a>
%H A025650 <a href="/index/Se#sequences_which_agree_for_a_long_time">Index entries for sequences which agree for a long time but are different</a>.
%F A025650 a(n) = A112765(A025617(n)). - _Amiram Eldar_, Jul 09 2025
%t A025650 With[{max = 10^10}, IntegerExponent[Sort[Flatten[Table[4^i*5^j, {i, 0, Log[4, max]}, {j, 0, Log[5, max/4^i]}]]], 5]] (* _Amiram Eldar_, Jul 09 2025 *)
%Y A025650 Cf. A025617, A025646, A112765.
%Y A025650 Differs from A025674 at a(1881).
%K A025650 nonn
%O A025650 1,6
%A A025650 _David W. Wilson_