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%I #19 Sep 25 2020 05:59:02
%S 1,5,10,25,50,100,125,250,500,625,1000,1250,2500,3125,5000,6250,10000,
%T 12500,15625,25000,31250,50000,62500,78125,100000,125000,156250,
%U 250000,312500,390625,500000,625000,781250,1000000,1250000,1562500,1953125
%N Numbers of form 5^i*10^j, with i, j >= 0.
%H Robert Israel, <a href="/A025625/b025625.txt">Table of n, a(n) for n = 1..10000</a>
%F Sum_{n>=1} 1/a(n) = (5*10)/((5-1)*(10-1)) = 25/18. - _Amiram Eldar_, Sep 25 2020
%F a(n) ~ exp(sqrt(2*log(5)*log(10)*n)) / sqrt(50). - _Vaclav Kotesovec_, Sep 25 2020
%p N:= 10^8: # for all terms <= N
%p 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 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 (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 Subsequence of A000351 and A011557.
%K easy,nonn
%O 1,2
%A _David W. Wilson_
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