A034731 - OEIS

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A034731

Dirichlet convolution of b_n=1 with Catalan numbers.

1, 2, 3, 7, 15, 46, 133, 436, 1433, 4878, 16797, 58837, 208013, 743034, 2674457, 9695281, 35357671, 129646266, 477638701, 1767268073, 6564120555, 24466283818, 91482563641, 343059672916, 1289904147339, 4861946609466 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Also number of objects fixed by permutations A057509/A057510 (induced by shallow rotation of general parenthesizations/plane trees).`
	FORMULA	`a(n) = Sum_{d divides n} C(d-1) where C() are the Catalan numbers (A000108).`
	CROSSREFS	`Occurs for first time in A073202 as row 16. Cf. A057546, A000108.` `Sequence in context: A039826 A161746 A045629 * A110888 A133736 A058698` `Adjacent sequences: A034728 A034729 A034730 * A034732 A034733 A034734`
	KEYWORD	`nonn`
	AUTHOR	`Erich Friedman (erich.friedman(AT)stetson.edu). More comments from Antti Karttunen (my_firstname.my_surname(AT)iki.fi) Jan 03 2003.`

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Last modified February 13 08:12 EST 2012. Contains 205451 sequences.