login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A065744 Number of 9's in the decimal expansion of 2^n. 11
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 3, 3, 2, 1, 1, 1, 2, 1, 2, 2, 1, 2, 1, 0, 0, 0, 1, 3, 3, 2, 3, 5, 3, 3, 3, 0, 0, 0, 2, 3, 1, 1, 1, 2, 2, 3, 3, 2, 1, 0, 2, 5, 2, 3, 2, 0, 2, 2, 3, 3, 1, 4, 3, 2, 1, 2, 2, 4, 4, 2, 6, 8, 3, 3, 3, 1, 1, 0, 2 (list; graph; refs; listen; history; text; internal format)
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

Cf. 0's A027870, 1's A065712, 2's A065710, 3's A065714, 4's A065715, 5's A065716, 6's A065717, 7's A065718, 8's A065719.

Sequence in context: A056223 A261143 A100013 * A016455 A278702 A060574

Adjacent sequences:  A065741 A065742 A065743 * A065745 A065746 A065747

KEYWORD

nonn,base

AUTHOR

Benoit Cloitre, Dec 04 2001

EXTENSIONS

More terms from Robert G. Wilson v, Dec 07 2001

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 26 06:08 EDT 2021. Contains 348257 sequences. (Running on oeis4.)