OFFSET
1,1
COMMENTS
Column 4 of A267232.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 14*a(n-1) -75*a(n-2) +190*a(n-3) -224*a(n-4) +96*a(n-5) for n>6.
Conjectures from Colin Barker, Feb 05 2018: (Start)
G.f.: x*(5 - 45*x + 135*x^2 - 145*x^3 + 20*x^4 + 24*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)^2).
a(n) = (2*(-3*2^(1+n) - 8*3^n + 41*4^n - 8) + 3*4^n*n) / 48 for n>1.
(End)
EXAMPLE
Some solutions for n=6:
..1....0....0....4....0....4....1....2....2....0....1....1....2....3....1....3
..4....4....3....2....1....4....2....3....0....2....3....4....0....1....3....1
..3....2....2....3....0....0....0....2....1....2....2....1....3....4....0....2
..0....4....3....1....4....3....1....0....2....1....1....3....4....0....2....3
..4....0....2....0....2....3....4....4....4....0....3....1....2....3....0....0
..2....2....2....0....1....0....0....3....1....0....1....3....3....3....3....4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 12 2016
STATUS
approved