A039973 An example of a d-perfect sequence: a(2*n) = 0, a(2*n-1) = A039965(n).

1, 0, 2, 0, 2, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 1, 0, 2, 0, 2, 0, 1, 0, 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, 2, 0, 1, 0, 2, 0, 2, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 1, 0, 2, 0, 2, 0, 1, 0, 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

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

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(2*n) = 0, a(2*n-1) = A039965(n). - Christian G. Bower, Jun 12 2005

Prog

(PARI)
C(n) = binomial(2*n, n)/(n+1);
A039965(n) = (((-1)^(n+1)*C(n-1)) % 3); \\ From A039965
A039973(n) = if(n%2, A039965((n+1)/2), 0); \\ Antti Karttunen, Feb 13 2019

Crossrefs

Cf. A039965.

Sequence in context: A164734 A090193 A039974 * A035171 A352567 A088700

Adjacent sequences: A039970 A039971 A039972 * A039974 A039975 A039976

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Christian G. Bower, Jun 12 2005

Bower's formula added to the name by Antti Karttunen, Feb 13 2019

Status

approved