A220562 T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly one horizontal or antidiagonal neighbor

1, 2, 1, 3, 5, 1, 5, 14, 13, 1, 8, 47, 64, 34, 1, 13, 149, 430, 292, 89, 1, 21, 481, 2604, 3966, 1332, 233, 1, 34, 1544, 16310, 45966, 36640, 6076, 610, 1, 55, 4965, 101052, 561636, 810778, 338581, 27716, 1597, 1, 89, 15957, 628269, 6743873, 19333688, 14298089

Offset

1,2

Comments

Table starts

.1.....2........3............5...............8..................13

.1.....5.......14...........47.............149.................481

.1....13.......64..........430............2604...............16310

.1....34......292.........3966...........45966..............561636

.1....89.....1332........36640..........810778............19333688

.1...233.....6076.......338581........14298089...........665748170

.1...610....27716......3128843.......252139015.........22926570957

.1..1597...126428.....28913910......4446314533........789539775889

.1..4181...576708....267196106.....78407942556......27190037181789

.1.10946..2630684...2469184016...1382674335890.....936366170726784

.1.28657.12000004..22817958901..24382584703194...32246430390993213

.1.75025.54738652.210862878471.429971411669361.1110497486239608510

Links

R. H. Hardin, Table of n, a(n) for n = 1..337

Example

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

Crossrefs

Column 2 is A001519(n+1)

Column 3 is A060801

Row 1 is A000045(n+1)

Sequence in context: A173588 A286942 A125076 * A215564 A189449 A239286

Adjacent sequences: A220559 A220560 A220561 * A220563 A220564 A220565

Keyword

nonn,tabl

Author

R. H. Hardin Dec 16 2012

Status

approved