1,2

An approximate "inverse" of A000045 (of the Fibonacci numbers).

Table of n, a(n) for n=1..88.

[seq(floor(log[(sqrt(5)+1)/2](n*sqrt(5))), n=1..120)];

(Scheme function:) (define (A072648 n) (cond ((zero? n) n) (else (floor->exact (/ (log (* n *Sqrt5*)) *LogPhi*)))))

(define *Sqrt5* (sqrt 5))

(define *Phi* (/ (1+ *Sqrt5*) 2))

(define *LogPhi* (log *Phi*))

Used to construct A072649.

Sequence in context: A196337 A064631 A298200 * A185585 A072945 A274004

Adjacent sequences: A072645 A072646 A072647 * A072649 A072650 A072651

nonn

Antti Karttunen, Jun 02 2002

approved