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.

A188690 Number of nX4 binary arrays without the pattern 0 1 0 diagonally, vertically, antidiagonally or horizontally.

Original entry on oeis.org

12, 144, 857, 4008, 20662, 120839, 708519, 3984317, 22096751, 123685638, 697749740, 3933600940, 22113174257, 124226310961, 698384857435, 3928070328882, 22091307667400, 124217141507585, 698440667872786
Offset: 1

Views

Author

R. H. Hardin Apr 08 2011

Keywords

Comments

Column 4 of A188695

Examples

			Some solutions for 5X4
..1..1..0..0....0..0..0..1....1..1..1..1....1..1..1..0....0..0..1..1
..1..0..0..0....1..0..0..1....0..0..0..1....1..1..1..0....0..0..1..1
..1..1..0..0....1..1..0..1....0..0..0..0....1..1..1..1....1..0..0..1
..1..1..0..0....1..1..0..0....1..0..0..0....1..1..0..1....1..1..0..1
..1..0..0..1....1..0..0..0....1..1..1..0....1..1..1..0....1..1..0..0
		

Formula

Empirical: a(n) = 8*a(n-1) -20*a(n-2) +38*a(n-3) +44*a(n-4) -252*a(n-5) -94*a(n-6) -173*a(n-7) +417*a(n-8) +2548*a(n-9) -384*a(n-10) +1193*a(n-11) -4772*a(n-12) -6984*a(n-13) +6677*a(n-14) -10923*a(n-15) +16477*a(n-16) +4376*a(n-17) -6808*a(n-18) +1546*a(n-19) -4577*a(n-20) +1179*a(n-21) +3261*a(n-22) -1466*a(n-23) -63*a(n-24) +121*a(n-25) -246*a(n-26) +361*a(n-27) -334*a(n-28) -3*a(n-29) +149*a(n-30) -66*a(n-31) +4*a(n-32) +2*a(n-33)