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 A025625 #23 Jul 06 2025 10:03:14
%S A025625 1,5,10,25,50,100,125,250,500,625,1000,1250,2500,3125,5000,6250,10000,
%T A025625 12500,15625,25000,31250,50000,62500,78125,100000,125000,156250,
%U A025625 250000,312500,390625,500000,625000,781250,1000000,1250000,1562500,1953125
%N A025625 Numbers of form 5^i*10^j, with i, j >= 0.
%H A025625 Robert Israel, <a href="/A025625/b025625.txt">Table of n, a(n) for n = 1..10000</a>
%F A025625 Sum_{n>=1} 1/a(n) = (5*10)/((5-1)*(10-1)) = 25/18. - _Amiram Eldar_, Sep 25 2020
%F A025625 a(n) ~ exp(sqrt(2*log(5)*log(10)*n)) / sqrt(50). - _Vaclav Kotesovec_, Sep 25 2020
%F A025625 a(n) = 5^A025655(n) * 10^A025687(n). - _R. J. Mathar_, Jul 06 2025
%p A025625 N:= 10^8: # for all terms <= N
%p A025625 sort([seq(seq(5^i*10^j, j=0..floor(log[10](N/5^i))),i=0..floor(log[5](N)))]); # _Robert Israel_, Nov 19 2019
%t A025625 Block[{a = 5, b = 10, n = 10^7}, Sort@ Flatten@ Table[a^p * b^q, {p, 0, Log[a, n]}, {q, 0, Log[b, n/(a^p)]}]] (* _Michael De Vlieger_, Nov 19 2019 *)
%o A025625 (PARI) list(lim)=my(v=List(), N); for(n=0, logint(lim\=1, 10), N=10^n; while(N<=lim, listput(v, N); N*=5)); Set(v) \\ _Charles R Greathouse IV_, Jan 10 2018
%Y A025625 Subsequence of A000351 and A011557.
%K A025625 easy,nonn
%O A025625 1,2
%A A025625 _David W. Wilson_