OFFSET
1,2
COMMENTS
Row 4 of A229637.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 9*a(n-1) + 21*a(n-2) - 270*a(n-3) - 357*a(n-4) + 2967*a(n-5) + 4906*a(n-6) - 10083*a(n-7) - 18957*a(n-8) + 15750*a(n-9) + 31293*a(n-10) - 13335*a(n-11) - 23929*a(n-12) + 6426*a(n-13) + 7824*a(n-14) - 1336*a(n-15) - 1152*a(n-16) + 96*a(n-17) + 64*a(n-18) for n > 21.
EXAMPLE
Some solutions for n=3:
0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 0 1 1 0 1 0
1 2 2 0 2 1 2 0 1 1 2 0 2 0 2 2 0 2 0 2 2
1 0 1 0 2 1 2 0 2 0 2 1 2 0 2 2 0 1 1 2 1
1 0 2 1 2 1 1 0 1 0 2 1 1 0 1 2 0 2 1 2 1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 27 2013
STATUS
approved