

A230686


T(n,k)=Number of nXk 0..6 arrays x(i,j) with each element horizontally or antidiagonally next to at least one element with value (x(i,j)+1) mod 7, and upper left element zero


7



0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 68, 360, 32, 0, 0, 0, 0, 2, 1500, 24050, 15624, 432, 0, 0, 0, 0, 8, 18468, 974548, 2756394, 575280, 5182, 0, 0, 0, 0, 32, 199358, 30543988, 296568384, 272728160, 19355400, 58298, 0, 0, 0, 0
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OFFSET

1,25


COMMENTS

Table starts
.0.0.0.....0........0.........0.........0...........0.........0.......0...0.0
.0.0.0.....0........0.........0.........0...........2.........8......32.120
.0.0.0.....0........0........68......1500.......18468....199358.2097950
.0.0.0.....2......360.....24050....974548....30543988.887242598
.0.0.0....32....15624...2756394.296568384.24842737670
.0.0.0...432...575280.272728160
.0.0.0..5182.19355400
.0.0.0.58298


LINKS

R. H. Hardin, Table of n, a(n) for n = 1..71


FORMULA

Empirical for row n:
n=2: a(n) = 4*a(n1) 4*a(n3) 8*a(n4) 12*a(n5) 17*a(n6) 10*a(n7) for n>8
Empirical for column k:
k=4: [order 9]
k=5: [order 11] for n>12


EXAMPLE

All solutions for n=4 k=4
..0..1..0..6....0..1..2..3
..2..3..5..4....0..6..4..5
..4..5..3..2....5..4..6..0
..6..0..1..0....3..2..1..0


CROSSREFS

Row 2 is A230529(n1)
Sequence in context: A019261 A019222 A019141 * A341001 A221836 A279372
Adjacent sequences: A230683 A230684 A230685 * A230687 A230688 A230689


KEYWORD

nonn,tabl


AUTHOR

R. H. Hardin, Oct 27 2013


STATUS

approved



