OFFSET
1,2
COMMENTS
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
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Christian G. Bower, Jun 12 2005
Formula added to the name by Antti Karttunen, Aug 15 2017
STATUS
approved