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 A025673 #17 Jul 09 2025 12:50:38
%S A025673 0,0,1,0,1,2,0,1,2,3,0,1,2,3,0,4,1,2,3,0,4,1,5,2,3,0,4,1,5,2,6,3,0,4,
%T A025673 1,5,2,6,3,0,7,4,1,5,2,6,3,0,7,4,1,8,5,2,6,3,0,7,4,1,8,5,2,9,6,3,0,7,
%U A025673 4,1,8,5,2,9,6,3,10,0,7,4,1,8,5,2,9,6,3,10,0,7,4,11,1,8,5,2,9,6,3,10,0,7,4,11,1
%N A025673 Exponent of 8 (value of j) in n-th number of form 5^i*8^j.
%H A025673 Amiram Eldar, <a href="/A025673/b025673.txt">Table of n, a(n) for n = 1..10000</a>
%H A025673 <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 A025673 a(n) = A244413(A025623(n)). - _Amiram Eldar_, Jul 09 2025
%t A025673 Take[Sort[Flatten[Table[{5^i 8^j,j},{i,0,20},{j,0,20}],1]][[;;,2]],120] (* _Harvey P. Dale_, Nov 10 2024 *)
%t A025673 With[{max = 10^11}, IntegerExponent[Sort[Flatten[Table[5^i*8^j, {i, 0, Log[5, max]}, {j, 0, Log[8, max/5^i]}]]], 8]] (* _Amiram Eldar_, Jul 09 2025 *)
%Y A025673 Cf. A025623, A025653, A244413.
%Y A025673 Differs from A025658 at a(2805).
%K A025673 nonn
%O A025673 1,6
%A A025673 _David W. Wilson_