OFFSET
1,1
COMMENTS
Row 2 of A214141.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 10*a(n-1) + 50*a(n-2) - 116*a(n-3) - 361*a(n-4) + 106*a(n-5) + 312*a(n-6).
Empirical: 3^n/4 +13^(n+1)/120 -(-1)^n/6 +(-2)^(n+1)/5 -2*(-4)^n/15 +41/120. - R. J. Mathar, Jul 07 2012
Empirical g.f.: x*(4 - 23*x - 113*x^2 + 118*x^3 + 260*x^4) / ((1 - x)*(1 + x)*(1 + 2*x)*(1 - 3*x)*(1 + 4*x)*(1 - 13*x)). - Colin Barker, Jul 22 2018
EXAMPLE
Some solutions for n=4:
..0..1..2..3..1....0..1..0..1..2....0..1..2..3..2....0..1..2..3..2
..3..4..3..1..2....1..0..1..2..3....1..2..3..0..3....1..4..3..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 05 2012
STATUS
approved