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Search: id:A074940
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| A074940 |
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Numbers having at least one 2 in their ternary representation. |
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+0
11
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| 2, 5, 6, 7, 8, 11, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 29, 32, 33, 34, 35, 38, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 83, 86, 87, 88, 89, 92
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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n such that 3 divides C(2n,n).
n such that central trinomial coefficient A002426(n) == 0 (mod 3). - Emeric Deutsch and Bruce Sagan, Dec 04 2003
Also n such that A092255(n)==0 mod (3) - Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 22 2004
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LINKS
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E. Deutsch and B. E. Sagan, Congruences for Catalan and Motzkin numbers and related sequences, J. Num. Theory 117 (2006), 191-215.
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FORMULA
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n such that coefficient of x^n equals 0 in prod(k>=0, 1-x^(3^k))
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CROSSREFS
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Complement of A005836.
Cf. A006996, A007089, A081603, A081610, A081605, A081606.
A039966(a(n)) = 0.
Sequence in context: A122806 A122546 A028739 this_sequence A028752 A028791 A080727
Adjacent sequences: A074937 A074938 A074939 this_sequence A074941 A074942 A074943
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KEYWORD
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easy,nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr) and Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 04 2002; revised Dec 03 2003
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EXTENSIONS
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More terms from Emeric Deutsch and Bruce Sagan, Dec 04 2003
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