A215020 a(n) = log_2( A182105(n) ).

0, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 2, 3, 0, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 2, 3, 4, 0, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 2, 3, 0, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 2, 3, 4, 5, 0, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 2, 3, 0, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 2, 3, 4, 0, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 2, 3, 0, 0, 1, 0, 0, 1, 2, 0, 0, 1

Offset: 1

Author

N. J. A. Sloane, Aug 01 2012

Keywords

• nonn

Comments

Apparently the leftmost positions of change with incrementing skew-binary numbers (A169683), see example. - Joerg Arndt, May 27 2016

Irregular table read by rows, where the k-th row counts from 0 up to the ruler function of k, A007814(k). - Allan C. Wechsler, Sep 26 2019

Examples

			From _Joerg Arndt_, May 27 2016: (Start)
The first nonnegative skew-binary numbers (dots denote zeros) are
n :  [skew-binary]  position of change
00:  [ . . . . . ]  -
01:  [ . . . . 1 ]  0
02:  [ . . . . 2 ]  0
03:  [ . . . 1 . ]  1
04:  [ . . . 1 1 ]  0
05:  [ . . . 1 2 ]  0
06:  [ . . . 2 . ]  1
07:  [ . . 1 . . ]  2
08:  [ . . 1 . 1 ]  0
09:  [ . . 1 . 2 ]  0
10:  [ . . 1 1 . ]  1
11:  [ . . 1 1 1 ]  0
12:  [ . . 1 1 2 ]  0
13:  [ . . 1 2 . ]  1
14:  [ . . 2 . . ]  2
15:  [ . 1 . . . ]  3
16:  [ . 1 . . 1 ]  0
17:  [ . 1 . . 2 ]  0
18:  [ . 1 . 1 . ]  1
19:  [ . 1 . 1 1 ]  0
20:  [ . 1 . 1 2 ]  0
21:  [ . 1 . 2 . ]  1
22:  [ . 1 1 . . ]  2
23:  [ . 1 1 . 1 ]  0
24:  [ . 1 1 . 2 ]  0
25:  [ . 1 1 1 . ]  1
26:  [ . 1 1 1 1 ]  0
27:  [ . 1 1 1 2 ]  0
28:  [ . 1 1 2 . ]  1
29:  [ . 1 2 . . ]  2
30:  [ . 2 . . . ]  3
31:  [ 1 . . . . ]  4
32:  [ 1 . . . 1 ]  0
33:  [ 1 . . . 2 ]  0
...
(End)
From _Allan C. Wechsler_, Sep 27 2019 (Start)
First few rows of irregular table derived from A007814 (see comments).
0
0 1
0
0 1 2
0
0 1
0
0 1 2 3
0
0 1
...
(End)
		

Links

• Wikipedia, Skew binary number system

Crossrefs

Cf. A182105, A082850, A007814.

Formula

a(n) = A082850(n) - 1. - Omar E. Pol, Jun 18 2019