%I #13 Sep 25 2020 05:50:25
%S 1,5,8,25,40,64,125,200,320,512,625,1000,1600,2560,3125,4096,5000,
%T 8000,12800,15625,20480,25000,32768,40000,64000,78125,102400,125000,
%U 163840,200000,262144,320000,390625,512000,625000,819200,1000000,1310720
%N Numbers of form 5^i*8^j, with i, j >= 0.
%H Amiram Eldar, <a href="/A025623/b025623.txt">Table of n, a(n) for n = 1..10000</a>
%F Sum_{n>=1} 1/a(n) = (5*8)/((5-1)*(8-1)) = 10/7. - _Amiram Eldar_, Sep 25 2020
%F a(n) ~ exp(sqrt(2*log(5)*log(8)*n)) / sqrt(40). - _Vaclav Kotesovec_, Sep 25 2020
%t n = 10^6; Flatten[Table[5^i*8^j, {i, 0, Log[5, n]}, {j, 0, Log[8, n/5^i]}]] // Sort (* _Amiram Eldar_, Sep 25 2020 *)
%Y Subsequence of A003592.
%K easy,nonn
%O 1,2
%A _David W. Wilson_