OFFSET
1,2
COMMENTS
Column 4 of A220652
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 36*a(n-1) +343*a(n-2) +2931*a(n-3) +9395*a(n-4) -79033*a(n-5) -304578*a(n-6) -236489*a(n-7) +2218923*a(n-8) +4968041*a(n-9) +5876393*a(n-10) +2942035*a(n-11) -19113725*a(n-12) -49387151*a(n-13) +6556425*a(n-14) +14194635*a(n-15) +42787183*a(n-16) -6329582*a(n-17) -8472580*a(n-18) -4501368*a(n-19) +750960*a(n-20) +970734*a(n-21) -47316*a(n-22) -42256*a(n-23) +786*a(n-24) +848*a(n-25)
EXAMPLE
Some solutions for n=3 0=self 1=nw 2=n 3=ne 4=w 6=e 7=sw 8=s 9=se (reciprocal directions total 10)
.68.49.00.78...89.69.49.00...68.46.46.48...00.69.47.00...89.69.46.48
.29.00.13.27...28.18.18.17...26.49.00.27...89.37.19.00...29.18.19.27
.00.16.34.00...26.24.23.00...00.00.13.00...23.16.46.14...00.12.36.14
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 17 2012
STATUS
approved