id:A152171 - OEIS Search Results

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G.f. := (1-sqrt(1-4*x+4*x^2-4*x^3))/(2(1-x+x^2)x)

+0
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1, 1, 1, 2, 5, 12, 29, 73, 190, 505, 1363, 3727, 10306, 28771, 80975, 229512, 654545, 1876899, 5408142, 15650939, 45470545, 132573406, 387775229, 1137575084, 3346189045, 9867291817, 29163523978, 86377998093, 256343194011 (list; graph; listen)

	OFFSET	`1,4`
	COMMENT	`a(n) is the number of Dyck paths of length n without the height of peaks 2 (mod 3) and the height of valleys 1 (mod 3)`
	CROSSREFS	`Sequence in context: A025273 A089372 A036671 this_sequence A132807 A101411 A042789` `Adjacent sequences: A152168 A152169 A152170 this_sequence A152172 A152173 A152174`
	KEYWORD	`nonn`
	AUTHOR	`Jun Ma (majun(AT)math.sinica.edu.tw), Nov 27 2008`

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.

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