OFFSET
1,1
COMMENTS
Row 2 of A223918.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/10080)*n^8 + (1/504)*n^7 + (1/40)*n^6 + (109/720)*n^5 + (259/480)*n^4 + (173/144)*n^3 + (4877/2520)*n^2 + (481/420)*n + 1.
Conjectures from Colin Barker, Feb 23 2018: (Start)
G.f.: x*(6 - 18*x + 50*x^2 - 82*x^3 + 88*x^4 - 62*x^5 + 29*x^6 - 8*x^7 + x^8) / (1 - x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.
(End)
EXAMPLE
Some solutions for n=3:
..1..2..0....0..0..2....1..0..0....0..0..0....0..1..1....1..2..0....0..1..0
..1..2..0....0..0..2....1..0..0....1..1..0....0..2..1....1..2..2....1..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 29 2013
STATUS
approved