A220718 T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly two king-move neighbors, without consecutive collinear links

1, 1, 1, 1, 8, 1, 1, 26, 26, 1, 1, 118, 226, 118, 1, 1, 463, 2243, 2243, 463, 1, 1, 1930, 21195, 72923, 21195, 1930, 1, 1, 7843, 201598, 2126423, 2126423, 201598, 7843, 1, 1, 32209, 1913495, 63806966, 168897201, 63806966, 1913495, 32209, 1, 1, 131698

Offset

1,5

Comments

Table starts

.1.......1..........1.............1..............1...............1

.1.......8.........26...........118............463............1930

.1......26........226..........2243..........21195..........201598

.1.....118.......2243.........72923........2126423........63806966

.1.....463......21195.......2126423......168897201.....14158198781

.1....1930.....201598......63806966....14158198781...3503850286857

.1....7843....1913495....1902974315..1166906554415.837962999003819

.1...32209...18172469...56814065240.96567512189416

.1..131698..172565016.1695753689937

.1..539466.1638746380

.1.2208130

.1

Links

R. H. Hardin, Table of n, a(n) for n = 1..84

Example

Some solutions for n=3 k=4 0=self 1=nw 2=n 3=ne 4=w 6=e 7=sw 8=s 9=se (reciprocal directions total 10)
.00.69.47.00...68.48.69.47...00.69.47.00...69.49.00.00...00.68.47.00
.68.34.17.78...29.27.39.17...69.34.16.47...00.17.17.78...00.23.69.48
.26.34.36.24...36.14.36.14...00.16.34.00...36.34.36.24...00.00.00.12

Crossrefs

Sequence in context: A155452 A147295 A174388 * A176283 A323324 A181543

Adjacent sequences: A220715 A220716 A220717 * A220719 A220720 A220721

Keyword

nonn,tabl

Author

R. H. Hardin Dec 18 2012

Status

approved