OFFSET
1,1
COMMENTS
Column 2 of A223467
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 20*a(n-1) -137*a(n-2) +299*a(n-3) +529*a(n-4) -2784*a(n-5) +973*a(n-6) +6475*a(n-7) -4402*a(n-8) -4888*a(n-9) +2878*a(n-10) +428*a(n-11) -408*a(n-12) +52*a(n-13)
EXAMPLE
Some solutions for n=3
.12..7...12..7....1..3...11.17...18.13...10..6....4..2...12..8....8.13....9.14
..8.12....8.12....3..7....7.12...12..8...16.11....8..5...18.12....4..8...13.19
.13..8....4..8....7.11...12.18...18.13...10..6...12..8...12..8....1..4....8.13
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 20 2013
STATUS
approved