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.

A302953 T(n,k) = Number of n X k 0..1 arrays with every element equal to 1, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

Original entry on oeis.org

0, 1, 0, 1, 3, 0, 2, 15, 11, 0, 3, 46, 86, 34, 0, 5, 161, 519, 587, 111, 0, 8, 601, 3626, 6531, 3815, 361, 0, 13, 2208, 26167, 87901, 80589, 25131, 1172, 0, 21, 8053, 185810, 1248691, 2104533, 998670, 164916, 3809, 0, 34, 29415, 1317541, 17374552, 58679318
Offset: 1

Views

Author

R. H. Hardin, Apr 16 2018

Keywords

Comments

Table starts
.0.....1.......1..........2............3...............5..................8
.0.....3......15.........46..........161.............601...............2208
.0....11......86........519.........3626...........26167.............185810
.0....34.....587.......6531........87901.........1248691...........17374552
.0...111....3815......80589......2104533........58679318.........1596912288
.0...361...25131.....998670.....50519822......2766909379.......147310312318
.0..1172..164916...12365841...1212025201....130376252119.....13578993819785
.0..3809.1083375..153141597..29081585941...6144174797769...1251888966185979
.0.12377.7114906.1896492042.697771332458.289545909430332.115412264434282781

Examples

			Some solutions for n=5, k=4
..0..1..1..0. .0..1..1..0. .0..1..0..1. .0..1..0..0. .0..0..0..1
..1..0..0..0. .0..0..0..1. .1..0..1..0. .1..0..1..1. .0..0..1..1
..1..0..0..0. .1..1..1..0. .0..0..0..1. .0..0..1..0. .1..1..0..1
..0..1..1..0. .1..1..0..1. .1..1..1..0. .0..0..0..0. .1..0..1..1
..1..1..0..1. .0..0..1..1. .0..0..1..1. .0..1..1..0. .0..0..0..0
		

Crossrefs

Column 2 is A180762.
Row 1 is A000045(n-1).
Row 2 is A232077(n-1).

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 3*a(n-1) +a(n-2) -2*a(n-4)
k=3: a(n) = 4*a(n-1) +15*a(n-2) +13*a(n-3) -2*a(n-4) -19*a(n-5) -3*a(n-6) +4*a(n-8)
k=4: [order 13]
k=5: [order 43] for n>44
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-2)
n=2: a(n) = 3*a(n-1) +a(n-2) +4*a(n-3) +4*a(n-4) for n>5
n=3: [order 7] for n>9
n=4: [order 24] for n>25
n=5: [order 73] for n>74