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.

A280180 T(n,k)=Number of nXk 0..1 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

0, 1, 1, 0, 2, 0, 3, 12, 12, 3, 3, 41, 60, 41, 3, 9, 103, 279, 279, 103, 9, 15, 263, 1082, 1633, 1082, 263, 15, 31, 656, 3931, 8759, 8759, 3931, 656, 31, 57, 1618, 13720, 43094, 63336, 43094, 13720, 1618, 57, 108, 3931, 46467, 202693, 421214, 421214, 202693, 46467
Offset: 1

Views

Author

R. H. Hardin, Dec 28 2016

Keywords

Comments

Table starts
...0....1......0........3.........3...........9...........15.............31
...1....2.....12.......41.......103.........263..........656...........1618
...0...12.....60......279......1082........3931........13720..........46467
...3...41....279.....1633......8759.......43094.......202693.........919058
...3..103...1082.....8759.....63336......421214......2665301.......16203600
...9..263...3931....43094....421214.....3755997.....31821879......258976696
..15..656..13720...202693...2665301....31821879....359880117.....3910652938
..31.1618..46467...919058..16203600...258976696...3910652938....56789421603
..57.3931.153650..4057457..95738359..2046791216..41205820599...798794739075
.108.9459.499289.17554353.553426602.15814457993.424186764568.10974204206787

Examples

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

Crossrefs

Column 1 is A105423(n-2).

Formula

Empirical for column k:
k=1: a(n) = 3*a(n-1) -5*a(n-3) +3*a(n-5) +a(n-6)
k=2: [order 10] for n>14
k=3: [order 21] for n>28
k=4: [order 45] for n>54