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URL: https://oeis.org/A237859

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A237859
T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with no element greater than all horizontal neighbors or less than all vertical neighbors.
8
2, 4, 4, 7, 14, 7, 12, 41, 41, 12, 21, 114, 184, 114, 21, 37, 325, 773, 773, 325, 37, 65, 943, 3373, 4826, 3373, 943, 65, 114, 2731, 15038, 31651, 31651, 15038, 2731, 114, 200, 7876, 66838, 213165, 315896, 213165, 66838, 7876, 200, 351, 22702, 295601, 1428967
OFFSET
1,1
COMMENTS
Table starts
...2.....4.......7........12..........21............37..............65
...4....14......41.......114.........325...........943............2731
...7....41.....184.......773........3373.........15038...........66838
..12...114.....773......4826.......31651........213165.........1428967
..21...325....3373.....31651......315896.......3255233........33328972
..37...943...15038....213165.....3255233......51576880.......810629762
..65..2731...66838...1428967....33328972.....810629762.....19525964230
.114..7876..295601...9520138...338653847...12628484789....465620654717
.200.22702.1306735..63406826..3440498469..196722783963..11103987320260
.351.65489.5781785.422805151.35005538562.3069861742669.265336172863532
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 2*a(n-1) -a(n-2) +a(n-3)
k=2: a(n) = 3*a(n-1) -2*a(n-2) +4*a(n-3) +2*a(n-4) +a(n-5)
k=3: [order 11]
k=4: [order 21]
k=5: [order 46]
k=6: [order 98]
EXAMPLE
Some solutions for n=4 k=4
..1..1..0..1..1....1..1..1..1..1....0..0..1..1..1....1..1..1..1..0
..1..1..0..1..1....1..1..0..0..0....0..0..0..1..1....0..0..1..1..0
..1..1..1..1..1....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..1..1..1..1....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..1..1..1..1....1..1..1..1..1....0..0..1..1..1....1..1..1..1..1
CROSSREFS
Column 1 is A005251(n+3)
Sequence in context: A227751 A268995 A205744 * A392417 A240338 A227103
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Feb 14 2014
STATUS
approved