

A123384


Number of bits in binary expansion of 10^n.


9



1, 4, 7, 10, 14, 17, 20, 24, 27, 30, 34, 37, 40, 44, 47, 50, 54, 57, 60, 64, 67, 70, 74, 77, 80, 84, 87, 90, 94, 97, 100, 103, 107, 110, 113, 117, 120, 123, 127, 130, 133, 137, 140, 143, 147, 150, 153, 157, 160, 163, 167, 170, 173, 177, 180, 183, 187, 190, 193, 196
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OFFSET

0,2


COMMENTS

Number of powers of 2 less than or equal to 10^n.  Peter Munn, Nov 13 2019


LINKS

Table of n, a(n) for n=0..59.


FORMULA

a(n) = 1 + floor(n/A007524) = 1 + floor(n/log_10(2)).  R. J. Mathar, Nov 12 2006
a(n) = 1 + A066343(n).  R. J. Mathar, Mar 02 2007
a(n) = A067497(n) for n >= 1.  Georg Fischer, Nov 02 2018


EXAMPLE

a(3)=10 because 10^3 = 1111101000_2.
10^1 = 10 = 1010_2 has 4 digits.


MAPLE

A007524 := log[10](2.0) ; for n from 0 to 40 do printf("%d, ", 1+floor(n/A007524)) ; od: # R. J. Mathar, Nov 12 2006
a:=n>nops(convert(10^n, base, 2)): seq(a(n), n=0..70); # Emeric Deutsch, Mar 26 2007


CROSSREFS

Cf. A000079, A011557, A066343, A067497.
Row 1 of A253635.
Sequence in context: A080600 A198266 A067497 * A138813 A310689 A184625
Adjacent sequences: A123381 A123382 A123383 * A123385 A123386 A123387


KEYWORD

base,nonn


AUTHOR

Andrew Caldwell (spongebobpj(AT)yahoo.com), Nov 09 2006


EXTENSIONS

More terms from Emeric Deutsch, Mar 26 2007


STATUS

approved



