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.

A209650 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 0 1 vertically.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 9, 36, 36, 8, 14, 81, 102, 64, 10, 22, 196, 270, 216, 100, 12, 35, 484, 798, 630, 390, 144, 14, 56, 1225, 2354, 2156, 1215, 636, 196, 16, 90, 3136, 7210, 7128, 4690, 2079, 966, 256, 18, 145, 8100, 22232, 24990, 16830, 8904, 3276, 1392, 324, 20, 234
Offset: 1

Views

Author

R. H. Hardin Mar 11 2012

Keywords

Comments

Table starts
..2...4....6....9....14.....22.....35......56.......90......145.......234
..4..16...36...81...196....484...1225....3136.....8100....21025.....54756
..6..36..102..270...798...2354...7210...22232....69570...218950....693810
..8..64..216..630..2156...7128..24990...87136...311040..1112150...4018716
.10.100..390.1215..4690..16830..65765..251160...994050..3911375..15639390
.12.144..636.2079..8904..34012.145775..597856..2579940.10954895..47622744
.14.196..966.3276.15386..61754.287140.1247736..5805450.26247900.122620446
.16.256.1392.4860.24808.103664.518700.2364992.11769120.56106300.279344520

Examples

			Some solutions for n=4 k=3
..1..1..1....1..1..1....1..1..0....0..0..0....0..1..0....0..0..0....0..1..0
..1..1..1....1..1..1....1..1..0....0..1..1....1..1..0....0..0..0....0..0..0
..1..1..1....0..1..0....1..1..0....0..1..0....0..0..0....0..0..0....0..0..0
..1..1..1....0..1..0....1..1..0....0..0..0....0..0..0....0..0..0....0..0..0
		

Crossrefs

Column 2 is A016742
Column 3 is A086113
Row 1 is A001611(n+2)
Row 2 is A207436
Row 3 is A207747

Formula

Empirical for column k:
k=1: a(n) = 2*n
k=2: a(n) = 4*n^2
k=3: a(n) = 2*n^3 + 6*n^2 - 2*n
k=4: a(n) = 9*n^3 + (9/2)*n^2 - (9/2)*n
k=5: a(n) = (7/2)*n^4 + 21*n^3 - (7/2)*n^2 - 7*n
k=6: a(n) = 22*n^4 + (88/3)*n^3 - 22*n^2 - (22/3)*n
k=7: a(n) = 7*n^5 + 70*n^4 + (35/3)*n^3 - (105/2)*n^2 - (7/6)*n