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.

A297654 T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 3 neighboring 1s.

Original entry on oeis.org

1, 2, 1, 4, 10, 1, 7, 43, 36, 1, 12, 140, 231, 126, 1, 21, 494, 1073, 1421, 454, 1, 37, 1845, 6838, 11024, 9033, 1632, 1, 65, 6757, 45036, 131044, 113252, 55706, 5854, 1, 114, 24479, 268655, 1580681, 2525244, 1105531, 346032, 21010, 1, 200, 89068, 1617465
Offset: 1

Views

Author

R. H. Hardin, Jan 02 2018

Keywords

Comments

Table starts
.1.....2........4..........7...........12.............21................37
.1....10.......43........140..........494...........1845..............6757
.1....36......231.......1073.........6838..........45036............268655
.1...126.....1421......11024.......131044........1580681..........16899640
.1...454.....9033.....113252......2525244.......56630842........1075678445
.1..1632....55706....1105531.....46187510.....1906300826.......63350980838
.1..5854...346032...11089103....864944851....65775301075.....3863740405975
.1.21010..2151932..110654243..16149058068..2265577299182...234680441414485
.1.75412.13364992.1101808354.300870617401.77814433907002.14203234114710492

Examples

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

Crossrefs

Column 2 is A202796.
Row 1 is A005251(n+2).

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 3*a(n-1) +a(n-2) +4*a(n-3)
k=3: [order 11]
k=4: [order 24]
k=5: [order 60]
Empirical for row n:
n=1: a(n) = 2*a(n-1) -a(n-2) +a(n-3)
n=2: a(n) = 3*a(n-1) -2*a(n-2) +13*a(n-3) +6*a(n-4) +12*a(n-5) +12*a(n-6)
n=3: [order 17]
n=4: [order 38]