login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A059939 a(n) = floor(log_2(n+1) - 1). 3
0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

REFERENCES

Y. S. Song, On the combinatorics of rooted binary phylogenetic trees, Annals of Combinatorics, 7, 2003, 365-379.

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1024

FORMULA

a(n) = A000523(n+1) - 1 = floor(log_10(A007931(n))).

EXAMPLE

a(6) = floor(log_2(7) - 1) = floor(1.807...) = 1;

a(7) = floor(log_2(8) - 1) = floor(2) = 2;

a(8) = floor(log_2(9) - 1) = floor(2.169...) = 2.

MATHEMATICA

Table[Floor[Log[2, n+1]-1], {n, 110}] (* Harvey P. Dale, Oct 04 2014 *)

PROG

(PARI) { a=0; p=4; for (n=1, 1024, if (n + 1 == p, a++; p*=2; ); write("b059939.txt", n, " ", a); ) } \\ Harry J. Smith, Jun 30 2009

CROSSREFS

Sequence in context: A108582 A071840 A000193 * A071842 A085141 A082896

Adjacent sequences:  A059936 A059937 A059938 * A059940 A059941 A059942

KEYWORD

easy,nonn

AUTHOR

Henry Bottomley, Feb 14 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 February 16 21:59 EST 2019. Contains 320200 sequences. (Running on oeis4.)