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A079442 Number of fixed points in range [A014137(n-1)..A014138(n)] of permutation A071663. 7
1, 1, 0, 3, 0, 9, 0, 21, 0, 45, 0, 99, 0, 195, 0, 399, 0, 801, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..18.

R. Donaghey, Automorphisms on Catalan trees and bracketing, J. Combin. Theory, Series B, 29 (1980), 75-90.

A. Karttunen, C-program for counting the initial terms of this sequence

A. Karttunen, Illustration of initial terms for trees of sizes n=3..11

FORMULA

For all n >= 0, a(2n+3)/3 = A079444(n).

CROSSREFS

Cf. A057505, A071663, A079438, A079441, A079443, A079444.

Occurs in A073202 as row 176609070820803.

Sequence in context: A201581 A164597 A167295 * A254006 A016645 A217764

Adjacent sequences:  A079439 A079440 A079441 * A079443 A079444 A079445

KEYWORD

nonn,more,hard

AUTHOR

Antti Karttunen Jan 27 2003

EXTENSIONS

Name corrected by Antti Karttunen, Dec 13 2017

STATUS

approved

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Last modified November 12 21:10 EST 2018. Contains 317116 sequences. (Running on oeis4.)