OFFSET
1,3
COMMENTS
Column 4 of A252930.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (13/1609445376000)*n^16 + (13/18289152000)*n^15 + (3947/149448499200)*n^14 + (20057/37362124800)*n^13 + (728009/114960384000)*n^12 + (312437/7185024000)*n^11 + (1303193/7315660800)*n^10 + (848039/1828915200)*n^9 + (11500417/20901888000)*n^8 - (1346209/373248000)*n^7 - (14478857/1149603840)*n^6 - (361673/8164800)*n^5 + (13716552599/33530112000)*n^4 + (454863863/1397088000)*n^3 - (207327073/86486400)*n^2 + (137883/80080)*n.
Empirical: G.f.: x^2*(-1 -16*x -190*x^2 -350*x^3 +1419*x^4 -3792*x^5 +7860*x^6 -11238*x^7 +11247*x^8 -8133*x^9 +4280*x^10 -1600*x^11 +401*x^12 -60*x^13+4*x^14) / (x-1)^17. - R. J. Mathar, Nov 23 2015
EXAMPLE
Some solutions for n=4
..0..0..1..2....0..0..0..0....0..0..1..1....0..1..1..1....0..1..1..1
..0..1..1..2....0..0..0..1....1..1..1..1....0..1..1..2....1..1..1..2
..1..1..1..2....0..0..1..2....1..1..1..1....1..1..1..2....1..1..1..2
..1..1..2..2....0..0..1..2....2..2..2..2....1..1..2..2....1..1..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 24 2014
STATUS
approved