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.

A230068 T(n,k)=Number of nXk 0..2 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value 2-x(i,j).

Original entry on oeis.org

0, 0, 0, 0, 9, 0, 0, 9, 9, 0, 0, 81, 45, 81, 0, 0, 225, 441, 441, 225, 0, 0, 1089, 3645, 15129, 3645, 1089, 0, 0, 3969, 31329, 281961, 281961, 31329, 3969, 0, 0, 16641, 266805, 6487209, 14082255, 6487209, 266805, 16641, 0, 0, 65025, 2277081, 137945025
Offset: 1

Views

Author

R. H. Hardin, Oct 08 2013

Keywords

Comments

Table starts
.0.....0.......0..........0.............0................0...................0
.0.....9.......9.........81...........225.............1089................3969
.0.....9......45........441..........3645............31329..............266805
.0....81.....441......15129........281961..........6487209...........137945025
.0...225....3645.....281961......14082255........793041921.........43142680647
.0..1089...31329....6487209.....793041921.....114228452529......15615593045649
.0..3969..266805..137945025...43142680647...15615593045649....5392746297039195
.0.16641.2277081.3020271849.2369158188849.2168295406671681.1888668174848027049

Examples

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

Crossrefs

Column 2 is A208556(n-2)

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 3*a(n-1) +6*a(n-2) -8*a(n-3)
k=3: a(n) = 7*a(n-1) +14*a(n-2) -8*a(n-3)
k=4: [order 10] for n>11
k=5: [order 16] for n>19