A219081 Hilltop maps: number of 4Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..1 4Xn array.

1, 149, 2469, 32945, 494713, 7561349, 113959413, 1715622809, 25868247057, 390055483301, 5880485889397, 88654851159857, 1336593648057193, 20150953522466741, 303802286301958197, 4580222640012373465

Offset: 1

Author

R. H. Hardin Nov 11 2012

Keywords

• nonn

Comments

Row 4 of A219078

Examples

			Some solutions for n=3
..1..0..1....0..1..0....0..1..0....0..1..0....0..1..0....1..1..1....0..0..0
..1..0..0....0..0..0....1..1..1....1..0..0....1..1..0....1..0..0....1..1..1
..1..1..1....1..0..1....0..1..1....1..0..1....1..1..0....1..1..1....1..1..0
..0..1..1....1..1..1....1..1..1....1..1..0....1..1..0....1..0..1....1..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..142

Formula

Empirical: a(n) = 10*a(n-1) +44*a(n-2) +384*a(n-3) +1502*a(n-4) +1612*a(n-5) -478*a(n-6) -4742*a(n-7) -13053*a(n-8) -13178*a(n-9) -7218*a(n-10) -8982*a(n-11) -108*a(n-12) +3888*a(n-13)