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 A039967 An example of a d-perfect sequence. 1
 1, 2, 2, 2, 0, 0, 0, 2, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 1, 1, 1, 0, 0, 0, 1, 1, 1, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 1, 1, 1, 0, 0, 0, 1, 1, 1, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = a(n-1) if n == 0 or 1 (mod 3). a(n) = 0 if n == 5,6, or 7 (mod 9). - Robert Israel, Sep 20 2015 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 D. Kohel, S. Ling and C. Xing, Explicit Sequence Expansions, in Sequences and their Applications, C. Ding, T. Helleseth, and H. Niederreiter, eds., Proceedings of SETA'98 (Singapore, 1998), 308-317, 1999. FORMULA a(n) = ((-1)^(n+1)*A001006(n-1)) mod 3. - Christian G. Bower, Jun 12 2005 a(n) = Catalan number(n) mod 3 = A000108(n) mod 3. - Ilya Gutkovskiy, Sep 18 2015 MAPLE seq(binomial(2*n, n)/(n+1) mod 3, n = 1 .. 100); # Robert Israel, Sep 20 2015 MATHEMATICA Table[Mod[CatalanNumber[n], 3], {n, 100}] (* Vincenzo Librandi, Sep 20 2015 *) PROG (MAGMA) [Catalan(n) mod 3: n in [1..100]]; // Vincenzo Librandi, Sep 20 2015 (PARI) a(n) = binomial(2*n, n)/(n+1) % 3; vector(100, n, a(n)) \\ Altug Alkan, Sep 28 2015 CROSSREFS Cf. A000108, A001006, A067397. Sequence in context: A028953 A037865 A039969 * A258133 A123186 A127323 Adjacent sequences:  A039964 A039965 A039966 * A039968 A039969 A039970 KEYWORD nonn AUTHOR EXTENSIONS More terms from Christian G. Bower, Jun 12 2005 STATUS approved

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Last modified October 15 04:33 EDT 2019. Contains 328026 sequences. (Running on oeis4.)