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.

A283543 T(n,k)=Number of nXk 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors.

Original entry on oeis.org

2, 4, 4, 7, 11, 8, 13, 27, 33, 16, 24, 76, 127, 98, 32, 44, 201, 578, 573, 291, 64, 81, 537, 2369, 4089, 2615, 865, 128, 149, 1444, 10069, 25532, 29558, 11903, 2570, 256, 274, 3859, 42664, 167920, 282773, 212441, 54211, 7637, 512, 504, 10339, 179733, 1094959
Offset: 1

Views

Author

R. H. Hardin, Mar 10 2017

Keywords

Comments

Table starts
....2.....4.......7........13..........24............44..............81
....4....11......27........76.........201...........537............1444
....8....33.....127.......578........2369.........10069...........42664
...16....98.....573......4089.......25532........167920.........1094959
...32...291....2615.....29558......282773.......2905717........29377334
...64...865...11903....212441.....3109801......49760703.......778500603
..128..2570...54211...1529463....34266804.....854841910.....20707472573
..256..7637..246869..11006233...377393657...14672363665....550220030803
..512.22693.1124239..79212552..4156954825..251901309671..14624495679716
.1024.67432.5119755.570077446.45786939720.4324419947902.388675661283840

Examples

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

Crossrefs

Column 1 is A000079.
Column 2 is A282990.
Row 1 is A000073(n+3).
Row 2 is A282641.

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 2*a(n-1) +3*a(n-2) -a(n-4)
k=3: a(n) = 5*a(n-1) -a(n-2) -7*a(n-3) +10*a(n-4) +4*a(n-5) -8*a(n-6)
k=4: [order 8]
k=5: [order 21]
k=6: [order 27]
k=7: [order 59]
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-2) +a(n-3)
n=2: a(n) = a(n-1) +3*a(n-2) +4*a(n-3)
n=3: a(n) = 2*a(n-1) +7*a(n-2) +11*a(n-3) -6*a(n-4) +11*a(n-5) -2*a(n-6)
n=4: [order 8]
n=5: [order 21]
n=6: [order 32]
n=7: [order 69]