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.

A279977 T(n,k) is the number of n X k 0..1 arrays with no element equal to a strict majority of its horizontal 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, 0, 0, 3, 0, 3, 9, 9, 0, 3, 24, 50, 31, 0, 9, 62, 221, 296, 108, 0, 15, 134, 822, 1922, 1650, 366, 0, 31, 277, 2669, 10491, 15511, 8666, 1205, 0, 57, 542, 8068, 50690, 124030, 118857, 43543, 3873, 0, 108, 1035, 23169, 226771, 887491, 1393359, 876704, 211650
Offset: 1

Views

Author

R. H. Hardin, Dec 24 2016

Keywords

Examples

			Table starts:
.0.....1.......0.........3...........3............9.............15
.0.....3.......9........24..........62..........134............277
.0.....9......50.......221.........822.........2669...........8068
.0....31.....296......1922.......10491........50690.........226771
.0...108....1650.....15511......124030.......887491........5870751
.0...366....8666....118857.....1393359.....14787217......144819856
.0..1205...43543....876704....15071233....237386464.....3444870482
.0..3873..211650...6281773...158391708...3703836674....79672440007
.0.12207.1002602..43997218..1627160233..56499013470..1801951754910
.0.37859.4652327.302544617.16409869901.846166990079.40020022178950
...
Some solutions for n=4 and k=4:
..0..1..0..0. .0..1..0..0. .0..1..0..1. .0..0..1..0. .0..1..0..1
..0..0..1..0. .0..1..1..0. .0..1..0..0. .1..0..1..0. .1..0..1..1
..1..1..1..1. .0..0..1..1. .1..0..1..1. .0..1..0..1. .1..0..1..1
..1..0..0..1. .0..0..1..0. .0..0..0..1. .1..0..0..1. .0..1..0..1
		

Crossrefs

Row 1 is A105423(n-2).

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 9*a(n-1) -30*a(n-2) +45*a(n-3) -30*a(n-4) +9*a(n-5) -a(n-6)
k=3: [order 9] for n>10
k=4: [order 24]
k=5: [order 38] for n>39
k=6: [order 96] for n>97
Empirical for row n:
n=1: a(n) = 3*a(n-1) -5*a(n-3) +3*a(n-5) +a(n-6)
n=2: [order 8] for n>10
n=3: [order 24] for n>30
n=4: [order 68] for n>78