A139817 2^n - number of digits of 2^n.

0, 1, 3, 7, 14, 30, 62, 125, 253, 509, 1020, 2044, 4092, 8188, 16379, 32763, 65531, 131066, 262138, 524282, 1048569, 2097145, 4194297, 8388601, 16777208, 33554424, 67108856, 134217719, 268435447, 536870903, 1073741814, 2147483638, 4294967286, 8589934582

Offset: 0

Author

Rolf Pleisch, May 23 2008

Keywords

• nonn
• base

Crossrefs

Cf. A000079, A055642.

Programs

Mathematica

Table[2^n-IntegerLength[2^n],{n,0,40}] (* Harvey P. Dale, Apr 05 2015 *)

PARI

a(n) = 2^n - length(digits(2^n)) \\ Michel Marcus, Jul 18 2013

Formula

a(n) = A000079(n) - A055642(A000079(n)). - Michel Marcus, Jul 18 2013

Extensions

More terms from N. J. A. Sloane, Jun 29 2008