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.

A240783 T(n,k)=Number of nXk 0..1 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..1 introduced in row major order.

Original entry on oeis.org

1, 1, 2, 1, 3, 4, 1, 4, 11, 8, 1, 6, 20, 34, 16, 1, 9, 46, 97, 111, 32, 1, 14, 97, 305, 459, 361, 64, 1, 22, 216, 959, 2167, 2187, 1172, 128, 1, 35, 472, 3033, 10150, 15332, 10442, 3809, 256, 1, 56, 1043, 9581, 47920, 106411, 108509, 49861, 12377, 512, 1, 90, 2296, 30354
Offset: 1

Views

Author

R. H. Hardin, Apr 12 2014

Keywords

Comments

Table starts
...1.....1.......1........1..........1...........1.............1..............1
...2.....3.......4........6..........9..........14............22.............35
...4....11......20.......46.........97.........216...........472...........1043
...8....34......97......305........959........3033..........9581..........30354
..16...111.....459.....2167......10150.......47920........226532........1071982
..32...361....2187....15332.....106411......746346.......5228820.......36701371
..64..1172...10442...108509....1120383....11677893.....121621207.....1269199948
.128..3809...49861...767834...11791412...182610635....2827515311....43857418181
.256.12377..238068..5434887..124095989..2856212777...65742420202..1515928067679
.512.40218.1136678.38467875.1306056075.44672652785.1528546759636.52397680462958

Examples

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

Crossrefs

Column 1 is A000079(n-1)
Column 2 is A180762
Row 2 is A001611(n+1)

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 3*a(n-1) +a(n-2) -2*a(n-4)
k=3: a(n) = 5*a(n-1) -a(n-2) -a(n-3) +4*a(n-4) -4*a(n-5) -3*a(n-6) +a(n-7)
k=4: [order 22]
k=5: [order 54]
Empirical for row n:
n=1: a(n) = a(n-1)
n=2: a(n) = 2*a(n-1) -a(n-3)
n=3: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -a(n-5)
n=4: [order 15]
n=5: [order 30] for n>34
n=6: [order 94]