OFFSET
1,1
COMMENTS
Conjecture: there are no more terms beyond 229.
EXAMPLE
For the first 10 terms of A320601, the fractions of 0's among the decimal digits of 2^k are:
2^10 = 1024, fraction of 0's = 1/4
2^11 = 2048, fraction of 0's = 1/4
2^12 = 4096, fraction of 0's = 1/4
2^17 = 131072, fraction of 0's = 1/6
2^20 = 1048576, fraction of 0's = 1/7
2^21 = 2097152, fraction of 0's = 1/7
2^22 = 4194304, fraction of 0's = 1/7
2^23 = 8388608, fraction of 0's = 1/7
2^26 = 67108864, fraction of 0's = 1/8
2^29 = 536870912, fraction of 0's = 1/9
So record minima are reached at k = 10, 17, 20, 26 and 29.
PROG
(PARI) lista(nn) = {my(kmin = oo, d, k); for(n=1, nn, d = digits(2^n); if (! vecmin(d), if ((k = #select(x->(x==0), d)/#d) < kmin, print1(n, ", "); kmin = k); ); ); } \\ Michel Marcus, Feb 15 2020
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Chai Wah Wu, Feb 11 2020
STATUS
approved