OFFSET
1,57
COMMENTS
These are vectors [u_1 ... u_n] such that
(i) u_i = 1,2 or 3,
(ii) u_i != u_{i+1},
(iii) Sum_{i=1..k} u_i != prime for k=1..n,
(iv) Sum_{i=k..n} u_i != prime for k=1..n.
Conjecture: There are infinitely many n > 0 with a(n) > 0. - Alois P. Heinz, Jan 27 2015
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1970
EXAMPLE
All solutions for n=5:
..1
..3
..2
..3
..1
CROSSREFS
KEYWORD
AUTHOR
R. H. Hardin, Jan 26 2015
STATUS
approved