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.

A240893 T(n,k)=Number of nXk 0..2 arrays with no element equal to a different number of vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order.

Original entry on oeis.org

1, 1, 1, 2, 4, 2, 4, 11, 11, 4, 8, 36, 57, 36, 8, 16, 116, 289, 289, 116, 16, 32, 376, 1485, 2362, 1485, 376, 32, 64, 1216, 7609, 19065, 19065, 7609, 1216, 64, 128, 3936, 38981, 154858, 245268, 154858, 38981, 3936, 128, 256, 12736, 199761, 1255585, 3146755
Offset: 1

Views

Author

R. H. Hardin, Apr 14 2014

Keywords

Comments

Table starts
...1.....1.......2.........4...........8.............16...............32
...1.....4......11........36.........116............376.............1216
...2....11......57.......289........1485...........7609............38981
...4....36.....289......2362.......19065.........154858..........1255585
...8...116....1485.....19065......245268........3146755.........40424861
..16...376....7609....154858.....3146755.......64074526.......1302610899
..32..1216...38981...1255585....40424861.....1302610899......41971040844
..64..3936..199761..10186158...519218802....26501432610....1352138182759
.128.12736.1023597..82615013..6669141957...539075345618...43565815810587
.256.41216.5245049.670126562.85661208693.10966382557858.1403705064843757

Examples

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

Crossrefs

Column 1 is A000079(n-2)
Column 2 is A206687

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1) for n>2
k=2: a(n) = 2*a(n-1) +4*a(n-2) for n>4
k=3: a(n) = 3*a(n-1) +8*a(n-2) +14*a(n-3) +4*a(n-4)
k=4: [order 16]
k=5: [order 48]