A039972 An example of a d-perfect sequence: a(n) = A007317(n) mod 3.

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

1,2

Comments

Odd bisection seems to be A006996. See also A039969. - Antti Karttunen, Aug 15 2017

Links

Antti Karttunen, Table of n, a(n) for n = 1..6561

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) = A007317(n) mod 3. - Christian G. Bower, Jun 12 2005

Prog

(PARI)
write_to_bfile(start_offset, vec, bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }
A039972_as_a_vector(size)= { my(A=vector(size)); for(j=1, size, A[j]=1+sum(k=1, j-1, A[k]*A[j-k])); apply(n->(n%3), A); }; \\ After Michael Somos' May 23 2005 code for A007317 and Christian G. Bower's formula for A039972.
write_to_bfile(1, A039972_as_a_vector(6561), "b039972_upto6561.txt"); \\ Antti Karttunen, Aug 15 2017

Crossrefs

Cf. A006996, A007317, A010872, A039969.

Sequence in context: A137677 A015818 A225869 * A344834 A344837 A031124

Adjacent sequences: A039969 A039970 A039971 * A039973 A039974 A039975

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Christian G. Bower, Jun 12 2005

Formula added to the name by Antti Karttunen, Aug 15 2017

Status

approved