A220624 Number of ways to reciprocally link elements of an 5Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor

1, 228, 4657, 243119, 8608738, 356768525, 13864972277, 553125347136, 21831846871613, 865461975018339, 34247958158855874, 1356237159188241529, 53691862459540232153, 2125854494007156918632, 84166119627538600335289

Offset

1,2

Comments

Row 5 of A220621

Links

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

Formula

Empirical: a(n) = 29*a(n-1) +557*a(n-2) -4948*a(n-3) -24662*a(n-4) +187560*a(n-5) +182180*a(n-6) -1893504*a(n-7) -127344*a(n-8) +6325072*a(n-9) +132352*a(n-10) -7384448*a(n-11) -1323456*a(n-12) +2439808*a(n-13) +987648*a(n-14) -7168*a(n-15) -69632*a(n-16) +32768*a(n-17)

Example

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

Crossrefs

Sequence in context: A302755 A064245 A201238 * A098246 A091551 A033528

Adjacent sequences: A220621 A220622 A220623 * A220625 A220626 A220627

Keyword

nonn

Author

R. H. Hardin Dec 17 2012

Status

approved