A220566 Number of ways to reciprocally link elements of an 5Xn array either to themselves or to exactly one horizontal or antidiagonal neighbor

1, 89, 1332, 36640, 810778, 19333688, 449429440, 10536960271, 246344047375, 5764617097479, 134855487893714, 3155067573838299, 73813420827751321, 1726896241431387347, 40401344327635974032, 945204561717125804080

Offset

1,2

Comments

Row 5 of A220562

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +332*a(n-2) +1166*a(n-3) -10416*a(n-4) -41922*a(n-5) +174048*a(n-6) +535206*a(n-7) -1872086*a(n-8) -2804534*a(n-9) +11470692*a(n-10) +3617576*a(n-11) -32706416*a(n-12) +4049368*a(n-13) +51508932*a(n-14) -14992866*a(n-15) -49988407*a(n-16) +16438786*a(n-17) +31549556*a(n-18) -9212528*a(n-19) -13108544*a(n-20) +2853616*a(n-21) +3512372*a(n-22) -487178*a(n-23) -584214*a(n-24) +44610*a(n-25) +58000*a(n-26) -2006*a(n-27) -3248*a(n-28) +34*a(n-29) +92*a(n-30) -a(n-32)

Example

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

Crossrefs

Sequence in context: A264253 A219929 A226544 * A301955 A241635 A105719

Adjacent sequences: A220563 A220564 A220565 * A220567 A220568 A220569

Keyword

nonn

Author

R. H. Hardin Dec 16 2012

Status

approved