OFFSET
1,2
COMMENTS
Column 1 of A211910.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..76
FORMULA
Empirical: a(n) = (1/8)*n^4 + (1/4)*n^3 - (9/8)*n^2 + (3/4)*n + 1 for n>1.
EXAMPLE
Some solutions for n=4:
..0........0........0........0........0........0........0........0
..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2
..3.4.5....3.4.5....3.0.4....3.4.5....3.4.5....3.4.3....3.4.5....3.4.5
..6.0.7.8..6.7.8.7..5.6.7.8..6.7.4.8..6.7.8.4..5.6.7.8..6.1.7.8..6.7.0.8
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 25 2012
STATUS
approved