OFFSET
0,33
LINKS
Harry J. Smith, Table of n, a(n) for n = 0..1000
EXAMPLE
2^12 = 4096 so a(12)=1.
MATHEMATICA
Table[ Count[ IntegerDigits[2^n], 9], {n, 0, 100} ]
PROG
(PARI)
Count(x, d)={ #select(t->t==d, digits(x)) }
a(n) = Count(2^n, 9) \\ Harry J. Smith, Oct 27 2009
(Python)
def A065744(n):
return str(2**n).count('9') # Chai Wah Wu, Feb 14 2020
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Benoit Cloitre, Dec 04 2001
EXTENSIONS
More terms from Robert G. Wilson v, Dec 07 2001
STATUS
approved