OFFSET
1,1
COMMENTS
Column 3 of A206668.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 26*a(n-1) -144*a(n-2) -1588*a(n-3) +18637*a(n-4) +5758*a(n-5) -751704*a(n-6) +1840094*a(n-7) +14513664*a(n-8) -65772588*a(n-9) -130792664*a(n-10) +1118371160*a(n-11) +21939840*a(n-12) -11122773609*a(n-13) +12058897820*a(n-14) +67650111988*a(n-15) -135206849805*a(n-16) -242499184542*a(n-17) +791308710878*a(n-18) +391513919157*a(n-19) -2894137633169*a(n-20) +570261077334*a(n-21) +6957579656654*a(n-22) -4843693048003*a(n-23) -10901474451808*a(n-24) +13280426659456*a(n-25) +9886997716394*a(n-26) -21783374723218*a(n-27) -1550353388521*a(n-28) +23200269912687*a(n-29) -8933522230705*a(n-30) -15488045412445*a(n-31) +13388405243555*a(n-32) +4905930909701*a(n-33) -10088874981494*a(n-34) +1430106930020*a(n-35) +4307101996461*a(n-36) -2512129319470*a(n-37) -739394091588*a(n-38) +1427826250529*a(n-39) -246681141171*a(n-40) -495751351484*a(n-41) +199766418707*a(n-42) +120977867459*a(n-43) -65754432424*a(n-44) -21474998274*a(n-45) +14092056596*a(n-46) +1990973380*a(n-47) -1895558392*a(n-48) +92084728*a(n-49) +79134384*a(n-50) -10328256*a(n-51) for n>55.
EXAMPLE
Some solutions for n=4:
..2..0..1..2....0..1..0..0....2..1..0..2....2..1..0..0....1..2..2..0
..2..0..1..1....2..2..2..1....1..0..2..0....2..1..1..2....0..1..0..0
..2..0..1..0....0..1..0..0....2..1..0..2....2..2..0..1....2..1..0..1
..0..0..0..0....2..1..2..1....1..2..1..0....0..1..2..2....1..1..1..1
..2..2..0..2....0..0..0..1....2..1..0..1....1..0..2..1....2..2..2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 11 2012
STATUS
approved