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.

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A282996 T(n,k) is the number of n X k 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors.

Original entry on oeis.org

2, 4, 4, 7, 11, 7, 13, 33, 33, 13, 24, 98, 163, 98, 24, 44, 291, 803, 803, 291, 44, 81, 865, 3971, 6547, 3971, 865, 81, 149, 2570, 19587, 53389, 53389, 19587, 2570, 149, 274, 7637, 96693, 435027, 720417, 435027, 96693, 7637, 274, 504, 22693, 477297, 3546870
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2017

Keywords

Examples

			Table starts:
...2.....4........7.........13...........24.............44...............81
...4....11.......33.........98..........291............865.............2570
...7....33......163........803.........3971..........19587............96693
..13....98......803.......6547........53389.........435027..........3546870
..24...291.....3971......53389.......720417........9706901........130854309
..44...865....19587.....435027......9706901......216173426.......4817792042
..81..2570....96693....3546870....130854309.....4817792042.....177509416175
.149..7637...477297...28911809...1763845523...107354061547....6539125324144
.274.22693..2355925..235681253..23775564134..2392171690343..240894164469261
.504.67432.11629027.1921212987.320481684651.53305366529469.8874303766960833
Some solutions for n=5 and k=4:
..0..1..1..0. .0..0..1..0. .1..0..0..0. .0..0..0..0. .1..0..0..0
..0..0..0..1. .0..0..0..1. .0..1..0..0. .1..0..0..0. .0..1..0..1
..0..1..1..0. .1..0..0..0. .0..1..0..1. .0..1..0..1. .0..0..0..0
..0..0..0..0. .1..0..0..0. .0..0..1..0. .1..0..1..0. .0..0..0..0
..0..0..0..1. .0..0..1..0. .1..0..0..1. .0..0..0..0. .0..0..1..0
		

Crossrefs

Diagonal is A067968.

Formula

Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2) +a(n-3);
k=2: a(n) = 2*a(n-1) +3*a(n-2) -a(n-4);
k=3: [order 9];
k=4: [order 15];
k=5: [order 36];
k=6: [order 69].
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