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.

A223062 T(n,k)=Number of nXk 0..3 arrays with all horizontally or vertically connected equal values in a straight line, and new values 0..3 introduced in row major order.

Original entry on oeis.org

1, 2, 2, 5, 10, 5, 15, 114, 114, 15, 51, 1473, 4865, 1473, 51, 187, 19360, 213469, 213469, 19360, 187, 715, 255045, 9383963, 31331820, 9383963, 255045, 715, 2795, 3361024, 412602889, 4606719559, 4606719559, 412602889, 3361024, 2795, 11051, 44294253
Offset: 1

Views

Author

R. H. Hardin Mar 13 2013

Keywords

Comments

Table starts
...1......2.........5...........15...............51.................187
...2.....10.......114.........1473............19360..............255045
...5....114......4865.......213469..........9383963...........412602889
..15...1473....213469.....31331820.......4606719559........677531592132
..51..19360...9383963...4606719559....2266567594841....1115636153544055
.187.255045.412602889.677531592132.1115636153544055.1837966217755803448

Examples

			Some solutions for n=3 k=4
..0..1..0..1....0..1..0..2....0..1..0..2....0..1..0..1....0..1..1..0
..2..2..0..1....2..1..0..2....2..3..0..2....2..1..2..2....0..2..3..0
..3..3..3..3....2..3..1..0....2..1..2..0....3..2..3..0....0..2..0..1
		

Crossrefs

Column 1 is A007581(n-1)

Formula

Empirical for column k:
k=1: a(n) = 7*a(n-1) -14*a(n-2) +8*a(n-3)
k=2: a(n) = 18*a(n-1) -71*a(n-2) +102*a(n-3) -48*a(n-4) for n>5
k=3: a(n) = 55*a(n-1) -515*a(n-2) +1337*a(n-3) -696*a(n-4) -1188*a(n-5) +1008*a(n-6) for n>7
k=4: [order 11 for n>12]