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.

A205318 T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every 2X2 subblock having the same number of equal edges, and new values 0..1 introduced in row major order.

Original entry on oeis.org

8, 20, 20, 56, 84, 56, 164, 376, 376, 164, 488, 1708, 2606, 1708, 488, 1460, 7784, 18152, 18152, 7784, 1460, 4376, 35500, 126536, 193664, 126536, 35500, 4376, 13124, 161928, 882182, 2068148, 2068148, 882182, 161928, 13124, 39368, 738636, 6150512
Offset: 1

Views

Author

R. H. Hardin Jan 25 2012

Keywords

Comments

Table starts
.....8.....20.......56........164..........488..........1460............4376
....20.....84......376.......1708.........7784.........35500..........161928
....56....376.....2606......18152.......126536........882182.........6150512
...164...1708....18152.....193664......2068148......22091516.......235994088
...488...7784...126536....2068148.....33865634.....554916092......9094954742
..1460..35500...882182...22091516....554916092...13956665238....351210375464
..4376.161928..6150512..235994088...9094954742..351210375464..13574876544398
.13124.738636.42881096.2521075824.149077423220.8839958693704.524918733085720

Examples

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

Crossrefs

Column 1 is A115099.

Formula

Empirical for column k:
k=1: a(n) = 4*a(n-1) -3*a(n-2)
k=2: a(n) = 6*a(n-1) -7*a(n-2) +2*a(n-3)
k=3: a(n) = 10*a(n-1) -24*a(n-2) +21*a(n-3) -6*a(n-4)
k=4: a(n) = 17*a(n-1) -81*a(n-2) +157*a(n-3) -140*a(n-4) +56*a(n-5) -8*a(n-6)
k=5: a(n) = 31*a(n-1) -321*a(n-2) +1569*a(n-3) -4179*a(n-4) +6420*a(n-5) -5671*a(n-6) +2668*a(n-7) -516*a(n-8)
k=6: (order 14 recurrence)
k=7: (order 20 recurrence)