id:A081601 - OEIS Search Results

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Numbers n such that 3 does not divide sum(k=0,n, C(2k,k) ).

+0
5

3, 9, 12, 27, 30, 36, 39, 81, 84, 90, 93, 108, 111, 117, 120, 243, 246, 252, 255, 270, 273, 279, 282, 324, 327, 333, 336, 351, 354, 360, 363, 729, 732, 738, 741, 756, 759, 765, 768, 810, 813, 819, 822, 837, 840, 846, 849, 972, 975, 981, 984, 999, 1002, 1008, 1011 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Apparently a(n)/3 (mod 2) = A010060(n), the Thue-Morse sequence` `a(n) is the smallest number with exactly n+1 partitions into distinct powers of 2 or of 3: A131996(a(n))=n+1 and A131996(m)<n+1 for m<a(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 06 2007`
	LINKS	`R. Stephan, Some divide-and-conquer sequences ...` `R. Stephan, Table of generating functions`
	FORMULA	`Apparently a(n) = 3*A005836(n)`
	CROSSREFS	`Cf. A006134, A083096.` `Equals A089118(n-1) + 1.` `Sequence in context: A096726 A155504 A022379 this_sequence A137344 A029524 A101537` `Adjacent sequences: A081598 A081599 A081600 this_sequence A081602 A081603 A081604`
	KEYWORD	`easy,nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 22 2003`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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