cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A280673 T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

1, 2, 2, 4, 11, 5, 11, 59, 82, 14, 30, 338, 858, 612, 41, 82, 1917, 10205, 12484, 4568, 122, 224, 10893, 119440, 310365, 181640, 34096, 365, 612, 61880, 1401470, 7533245, 9439606, 2642832, 254496, 1094, 1672, 351541, 16438612, 183331502, 474736149
Offset: 1

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Author

R. H. Hardin, Jan 07 2017

Keywords

Comments

Table starts
....1.........2............4..............11...............30................82
....2........11...........59.............338.............1917.............10893
....5........82..........858...........10205...........119440...........1401470
...14.......612........12484..........310365..........7533245.........183331502
...41......4568.......181640.........9439606........474736149.......23952262535
..122.....34096......2642832.......287101721......29920114246.....3130289979912
..365....254496.....38452768......8732086113....1885698283255...409089889172506
.1094...1899584....559481408....265582964074..118845116023725.53463025958093933
.3281..14178688...8140361856...8077601392565.7490149091439288
.9842.105831168.118440917248.245677069239189

Examples

			Some solutions for n=3 k=4
..0..1..0..0. .0..1..0..2. .0..1..0..1. .0..0..1..0. .0..1..1..0
..0..1..2..1. .2..0..2..1. .0..2..1..0. .2..2..1..1. .2..0..2..0
..1..2..0..0. .2..1..0..2. .2..0..2..0. .1..0..2..2. .1..0..1..1
		

Crossrefs

Column 1 is A007051(n-1).
Column 2 is A209094.
Row 1 is A021006(n-3).

Formula

Empirical for column k:
k=1: a(n) = 4*a(n-1) -3*a(n-2)
k=2: a(n) = 8*a(n-1) -4*a(n-2) for n>3
k=3: a(n) = 14*a(n-1) +8*a(n-2)
k=4: a(n) = 29*a(n-1) +44*a(n-2) -27*a(n-3) -81*a(n-4) for n>5
k=5: [order 8] for n>9
k=6: [order 20] for n>22
Empirical for row n:
n=1: a(n) = 2*a(n-1) +2*a(n-2) for n>4
n=2: a(n) = 5*a(n-1) +6*a(n-2) -11*a(n-3) -7*a(n-4) +4*a(n-5) for n>6
n=3: [order 18] for n>20
n=4: [order 73] for n>78
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