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.

A283572 T(n,k) = Number of n X k 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element.

Original entry on oeis.org

0, 0, 0, 1, 4, 0, 2, 26, 16, 0, 5, 72, 169, 68, 0, 12, 282, 674, 1108, 256, 0, 26, 908, 4313, 6812, 6453, 924, 0, 56, 2832, 21186, 67892, 60802, 36038, 3232, 0, 118, 8856, 104464, 509952, 945100, 528436, 194173, 11044, 0, 244, 26750, 513458, 3890056, 10919674
Offset: 1

Views

Author

R. H. Hardin, Mar 11 2017

Keywords

Comments

Table starts
.0......0........1..........2............5.............12...............26
.0......4.......26.........72..........282............908.............2832
.0.....16......169........674.........4313..........21186...........104464
.0.....68.....1108.......6812........67892.........509952..........3890056
.0....256.....6453......60802.......945100.......10919674........129527524
.0....924....36038.....528436.....12699250......226897932.......4173039716
.0...3232...194173....4441052....164714523.....4558585174.....129997769458
.0..11044..1021432...36589848...2089140956....89724600000....3965206666608
.0..37104..5275885..296555892..26034179747..1736716820366..118919078661476
.0.122984.26869458.2373574616.320066184088.33188681249924.3520469545329364

Examples

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

Crossrefs

Column 2 is A283036.
Row 1 is A073778(n-1).

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 4*a(n-1) +2*a(n-2) -12*a(n-3) -11*a(n-4) +4*a(n-5) +6*a(n-6) -a(n-8)
k=3: [order 12]
k=4: [order 16]
k=5: [order 42]
k=6: [order 54]
Empirical for row n:
n=1: a(n) = 2*a(n-1) +a(n-2) -3*a(n-4) -2*a(n-5) -a(n-6)
n=2: a(n) = 2*a(n-1) +5*a(n-2) +2*a(n-3) -17*a(n-4) -24*a(n-5) -16*a(n-6)
n=3: [order 12]
n=4: [order 16]
n=5: [order 42]
n=6: [order 64]