A220625 Number of ways to reciprocally link elements of an 6Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

1, 733, 28373, 3466455, 262680517, 24177895648, 2054706174413, 180411767818111, 15630369162961753, 1361611598697855401, 118348460320274885509, 10296062072472866977053, 895398179175506044479552

Offset: 1

Author

R. H. Hardin Dec 17 2012

Keywords

• nonn

Comments

Row 6 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..6..4....6..4..0....0..6..4....0..0..0....0..9..0....0..0..0....9..6..4
..0..0..0....6..4..0....9..9..0....0..9..0....9..7..1....0..0..0....0..1..7
..0..7..0....0..0..0....0..1..1....0..7..1....3..1..7....6..4..0....0..3..0
..3..7..0....9..7..0....6..4..7....3..0..0....0..3..0....6..4..7....0..6..4
..3..0..0....3..1..0....0..3..0....9..7..0....0..7..0....0..3..0....0..6..4
..6..4..0....0..6..4....0..6..4....3..1..0....3..0..0....0..0..0....0..6..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 63*a(n-1) +2862*a(n-2) -60440*a(n-3) -824202*a(n-4) [phone]*a(n-5) -20045386*a(n-6) -921241585*a(n-7) [phone]*a(n-8) [phone]*a(n-9) -97429928112*a(n-10) [phone]*a(n-11) [phone]*a(n-12) -1932297359512*a(n-13) -1293178837092*a(n-14) [phone]*a(n-15) -3341781023928*a(n-16) -7386155450412*a(n-17) [phone]*a(n-18) -14572332601872*a(n-19) -15900073555920*a(n-20) [phone]*a(n-21) -1615780730832*a(n-22) -14531450950368*a(n-23) [phone]*a(n-24) [phone]*a(n-25) -23935477836*a(n-26) [phone]*a(n-27) [phone]*a(n-28) [phone]*a(n-29) -35095894230*a(n-30) -6841941084*a(n-31) -750501810*a(n-32) [phone]*a(n-33) -8202438*a(n-34) -1789695*a(n-35) -552825*a(n-36)