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A195600 Continued fraction for beta = 3/(2*log(alpha/2)); alpha = A195596. 7
1, 1, 20, 3, 2, 7, 1, 1, 1, 12, 1, 5, 1, 91, 1, 1, 3, 87, 2, 1, 1, 1, 1, 3, 1, 9, 3, 2, 1, 1, 1, 1, 190, 1, 3, 1, 82, 2, 1, 1, 1, 2, 1, 1, 1, 6, 1, 2, 12, 6, 2, 2, 2, 3, 2, 1, 1, 1, 2, 3, 21, 1, 1, 12, 1, 7, 3, 2, 26, 3, 2, 1, 1, 1, 9, 1, 15, 4, 3, 3, 1, 3, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
beta is used to measure the expected height of random binary search trees.
LINKS
B. Reed, The height of a random binary search tree, J. ACM, 50 (2003), 306-332.
FORMULA
beta = 3/(2*log(alpha/2)) = 3*alpha/(2*alpha-2), where alpha = A195596 = -1/W(-exp(-1)/2) and W is the Lambert W function.
A195582(n)/A195583(n) = alpha*log(n) - beta*log(log(n)) + O(1).
EXAMPLE
1.95302570335815413945406288542575380414251340201036319609354...
MAPLE
with(numtheory):
alpha:= solve(alpha*log((2*exp(1))/alpha)=1, alpha):
beta:= 3/(2*log(alpha/2)):
cfrac(evalf(beta, 130), 100, 'quotients')[];
MATHEMATICA
beta = 3/(2+2*ProductLog[-1/(2*E)]); ContinuedFraction[beta, 83] (* Jean-François Alcover, Jun 20 2013 *)
CROSSREFS
Cf. A195599 (decimal expansion), A195601 (Engel expansion), A195581, A195582, A195583, A195596, A195597, A195598.
Sequence in context: A040390 A040391 A255860 * A118295 A070645 A248136
KEYWORD
nonn,cofr
AUTHOR
Alois P. Heinz, Sep 21 2011
STATUS
approved

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Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)