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A220652 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 3-loops 7
1, 1, 1, 1, 4, 1, 1, 23, 23, 1, 1, 83, 333, 83, 1, 1, 344, 4352, 4352, 344, 1, 1, 1441, 59846, 192413, 59846, 1441, 1, 1, 5881, 816159, 8627817, 8627817, 816159, 5881, 1, 1, 24220, 11131560, 389859889, 1233993907, 389859889, 11131560, 24220, 1, 1, 99767 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

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

.1.......4..........23.............83..............344..............1441

.1......23.........333...........4352............59846............816159

.1......83........4352.........192413..........8627817.........389859889

.1.....344.......59846........8627817.......1233993907......179768901595

.1....1441......816159......389859889.....179768901595....85240331175084

.1....5881....11131560....17592276986...26120030149221.40274546959211319

.1...24220...151872860...793772500717.3794284713986274

.1...99767..2071881506.35817153012658

.1..410363.28265332768

.1.1688864

.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)

.00.00.78.78...69.47.00.78...69.47.68.48...00.78.69.47...68.48.79.00

.69.34.23.27...36.14.37.28...38.16.24.28...39.28.38.17...29.23.79.18

.00.16.34.00...00.36.46.24...26.46.46.24...00.12.23.00...00.13.00.12

CROSSREFS

Sequence in context: A015113 A016519 A113716 * A169654 A088158 A136449

Adjacent sequences:  A220649 A220650 A220651 * A220653 A220654 A220655

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Dec 17 2012

STATUS

approved

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Last modified January 21 05:39 EST 2020. Contains 331104 sequences. (Running on oeis4.)