OFFSET
1,2
COMMENTS
Row 5 of A220562
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 8*a(n-1) +332*a(n-2) +1166*a(n-3) -10416*a(n-4) -41922*a(n-5) +174048*a(n-6) +535206*a(n-7) -1872086*a(n-8) -2804534*a(n-9) +11470692*a(n-10) +3617576*a(n-11) -32706416*a(n-12) +4049368*a(n-13) +51508932*a(n-14) -14992866*a(n-15) -49988407*a(n-16) +16438786*a(n-17) +31549556*a(n-18) -9212528*a(n-19) -13108544*a(n-20) +2853616*a(n-21) +3512372*a(n-22) -487178*a(n-23) -584214*a(n-24) +44610*a(n-25) +58000*a(n-26) -2006*a(n-27) -3248*a(n-28) +34*a(n-29) +92*a(n-30) -a(n-32)
EXAMPLE
Some solutions for n=3 0=self 3=ne 4=w 6=e 7=sw (reciprocal directions total 10)
..0..0..0....6..4..0....6..4..7....0..0..0....0..6..4....6..4..0....0..0..7
..0..0..0....0..0..0....0..3..0....0..6..4....6..4..7....6..4..0....0..3..0
..0..0..7....6..4..0....0..0..0....0..0..0....0..3..0....0..0..0....0..0..7
..0..3..0....6..4..0....6..4..7....6..4..0....0..0..0....0..7..0....0..3..0
..0..0..0....6..4..0....0..3..0....6..4..0....0..0..0....3..0..0....0..6..4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 16 2012
STATUS
approved