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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
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: A345378 A071840 A000193 * A071842 A344517 A085141
KEYWORD
easy,nonn
AUTHOR
Henry Bottomley, Feb 14 2001
STATUS
approved

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Last modified March 28 07:48 EDT 2024. Contains 371235 sequences. (Running on oeis4.)