OFFSET
1,1
COMMENTS
Column 4 of A205335
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 18*a(n-1) +162*a(n-2) -1630*a(n-3) -7292*a(n-4) +40266*a(n-5) +153218*a(n-6) -289954*a(n-7) -912699*a(n-8) +408092*a(n-9) -10757308*a(n-10) -14129504*a(n-11) +156955072*a(n-12) +97653472*a(n-13) -903632160*a(n-14) +1868643200*a(n-15) +1929652736*a(n-16) -19338232320*a(n-17) +24779127808*a(n-18) +69276303360*a(n-19) -225213616128*a(n-20) +28917637120*a(n-21) +670518738944*a(n-22) -903935393792*a(n-23) -187621441536*a(n-24) +744869068800*a(n-25) -53941895168*a(n-26) -180004847616*a(n-27) -335544320*a(n-28) +3154116608*a(n-29) for n>31
EXAMPLE
Some solutions for n=4
..0..0..1..2..0....0..1..0..2..1....0..0..1..0..1....0..0..0..0..0
..1..0..1..1..1....2..2..1..1..0....2..0..2..1..0....1..2..0..0..1
..1..2..0..0..1....1..2..0..1..2....2..0..0..0..2....0..1..1..0..1
..2..2..0..1..0....0..0..2..1..1....0..1..2..0..2....0..1..0..1..2
..1..0..2..2..1....0..1..2..2..2....1..0..1..1..0....2..0..1..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 26 2012
STATUS
approved