OFFSET
1,3
LINKS
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. DOI: 10.1007/978-1-4471-0551-0_23
FORMULA
a(n) = ((-1)^(n+1)*A007317(n)) mod 3 - Christian G. Bower, Jun 12 2005
a(n) = A001405(n-1) mod 3. - John M. Campbell, Jul 19 2016
MATHEMATICA
Table[Mod[Binomial[n - 1, Floor[(n - 1)/2]], 3], {n, 120}] (* or *)
Table[Function[n, Mod[-(-1)^(n + 1) Sum[Binomial[n, k] CatalanNumber@ k, {k, 0, n}], 3]][n - 1], {n, 120}] (* Michael De Vlieger, Jul 19 2016 *)
PROG
(Magma) [Binomial(n, Floor(n/2)) mod 3: n in [0..140]]; // Vincenzo Librandi, Jul 20 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Christian G. Bower, Jun 12 2005
STATUS
approved