OFFSET
1,3
COMMENTS
Row 5 of A220632
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 16*a(n-1) -39*a(n-2) -186*a(n-3) +419*a(n-4) +1024*a(n-5) -1049*a(n-6) -2258*a(n-7) +861*a(n-8) +2000*a(n-9) -133*a(n-10) -586*a(n-11) -16*a(n-12) +32*a(n-13) for n>17
EXAMPLE
Some solutions for n=3 0=self 3=ne 4=w 6=e 7=sw (reciprocal directions total 10)
.00.67.47...00.67.47...00.00.00...00.00.00...00.00.00...00.67.47...00.00.00
.36.34.00...36.34.00...00.00.00...00.67.47...00.67.47...36.34.00...00.00.00
.00.67.47...00.00.00...00.00.00...36.34.00...36.34.00...00.00.00...00.00.00
.36.34.00...00.67.47...00.67.47...00.67.47...00.00.00...00.00.00...00.00.00
.00.00.00...36.34.00...36.34.00...36.34.00...00.00.00...00.00.00...00.00.00
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 17 2012
STATUS
approved