id:A080972 - OEIS Search Results

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a(n) = A080969(n)/A080967(A080979(A080970(n))).

+0
5

1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 3, 1, 2, 1, 4, 1, 2, 1, 2, 2, 3, 3, 1, 2, 2, 1, 2, 4, 1, 1, 2, 1, 4, 4, 1, 2, 2, 1, 2, 4, 1, 2, 4, 2, 4, 1, 1, 4, 4, 1, 4, 1, 2, 1, 4, 4, 2, 1, 4, 4, 2, 4, 4, 2, 1 (list; graph; listen)

	OFFSET	`0,4`
	COMMENT	`Donaghey shows in his paper that the orbit size (under the automorphism A057505/A057506) of each non-branch-reduced tree encoded by A080971(n) is divisible by the orbit size of the corresponding branch-reduced tree. This sequence gives the corresponding ratio.`
	REFERENCES	`R. Donaghey, Automorphisms on Catalan trees and bracketing, J. Combin. Theory, Series B, 29 (1980), 75-90.`
	CROSSREFS	`Sequence in context: A027354 A102673 A085297 this_sequence A037814 A118668 A044925` `Adjacent sequences: A080969 A080970 A080971 this_sequence A080973 A080974 A080975`
	KEYWORD	`nonn`
	AUTHOR	`Antti Karttunen (my_firstname.my_surname(AT)iki.fi) Mar 02 2003`

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Last modified December 19 21:04 EST 2009. Contains 171054 sequences.

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