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.

A267719 T(n,k)=Number of nXk 0..1 arrays with every repeated value in every row and column greater than the previous repeated value.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 9, 36, 36, 9, 12, 81, 102, 81, 12, 16, 144, 270, 270, 144, 16, 20, 256, 546, 872, 546, 256, 20, 25, 400, 1080, 1915, 1915, 1080, 400, 25, 30, 625, 1866, 4266, 4444, 4266, 1866, 625, 30, 36, 900, 3186, 7879, 10489, 10489, 7879, 3186, 900, 36, 42, 1296
Offset: 1

Views

Author

R. H. Hardin, Jan 19 2016

Keywords

Comments

Table starts
..2....4....6.....9.....12.....16.....20......25......30.......36.......42
..4...16...36....81....144....256....400.....625.....900.....1296.....1764
..6...36..102...270....546...1080...1866....3186....5010.....7830....11550
..9...81..270...872...1915...4266...7879...14632...24440....40816....63714
.12..144..546..1915...4444..10489..20226...39485...68430...119560...192852
.16..256.1080..4266..10489..26906..54887..114392..209470...385962...656670
.20..400.1866..7879..20226..54887.116036..255009..481390...932245..1627470
.25..625.3186.14632..39485.114392.255009..592110.1179367..2391952..4403235
.30..900.5010.24440..68430.209470.481390.1179367.2411426..5148115..9689432
.36.1296.7830.40816.119560.385962.932245.2391952.5148115.11438402.22656990

Examples

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

Crossrefs

Column 1 is A002620(n+2).
Column 2 is A030179(n+2).

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1) -2*a(n-3) +a(n-4)
k=2: a(n) = 2*a(n-1) +2*a(n-2) -6*a(n-3) +6*a(n-5) -2*a(n-6) -2*a(n-7) +a(n-8)
k=3: [order 12]
k=4: [order 16] for n>18
k=5: [order 20] for n>22
k=6: [order 24] for n>27
k=7: [order 28] for n>30