%I
%S 1,2,4,7,11,15,20,26,33,40,48,57,67,78,89,101,114,128,142,157,173,190,
%T 208,226,245,265,286,307,329,352,376,400,425,451,478,506,534,563,593,
%U 624,655,687,720,754,789,824,860,897,935,973,1012,1052,1093,1135,1177,1220
%N Index of 5^n within sequence of numbers of form 5^i*8^j.
%o (PARI) a(n)=my(N=1); n+1+sum(i=1, n, logint(N*=5, 8)); \\ _Charles R Greathouse IV_, Jan 16 2018
%o (PARI) first(n)=my(s, N=1/5); vector(n+1, i, s+=logint(N*=5, 8)+1) \\ _Charles R Greathouse IV_, Jan 16 2018
%Y Differs from A025703 at a(84).
%K nonn
%O 1,2
%A _David W. Wilson_
