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.

A280859 T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its king-move neighbors and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

1, 2, 2, 4, 9, 4, 11, 29, 29, 11, 30, 110, 46, 110, 30, 82, 442, 96, 96, 442, 82, 224, 1708, 256, 124, 256, 1708, 224, 612, 6596, 678, 216, 216, 678, 6596, 612, 1672, 25624, 1698, 462, 282, 462, 1698, 25624, 1672, 4568, 99432, 4358, 1005, 491, 491, 1005, 4358
Offset: 1

Views

Author

R. H. Hardin, Jan 09 2017

Keywords

Comments

Table starts
....1......2.....4...11...30...82..224...612..1672...4568...12480...34096
....2......9....29..110..442.1708.6596.25624.99432.385584.1495696.5802080
....4.....29....46...96..256..678.1698..4358.11218..28650...73354..188066
...11....110....96..124..216..462.1005..2010..3907...7756...15749...31804
...30....442...256..216..282..491..968..1857..3220...5281....8574...14339
...82...1708...678..462..491..712.1202..2268..4220...7108...11240...17330
..224...6596..1698.1005..968.1202.1738..2877..5244...9569...15872...24653
..612..25624..4358.2010.1857.2268.2877..4124..6722..12044...21713...35572
.1672..99432.11218.3907.3220.4220.5244..6722..9562..15351...27000...48087
.4568.385584.28650.7756.5281.7108.9569.12044.15351..21752...34547...59836

Examples

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

Crossrefs

Column 1 is A021006(n-3).

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1) +2*a(n-2) for n>4
k=2: a(n) = 4*a(n-1) -2*a(n-2) +8*a(n-3) -8*a(n-4) for n>5
k=3: a(n) = 2*a(n-1) +4*a(n-3) -a(n-4) +2*a(n-6) -2*a(n-7) for n>9
k=4: [order 12] for n>16
k=5: [order 12] for n>18
k=6: [order 16] for n>22
k=7: [order 23] for n>29