A220456 Equals one maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nX2 array

2, 4, 22, 74, 250, 848, 2851, 9535, 31888, 106775, 357028, 1193927, 3992279, 13348541, 44630321, 149215567, 498878032, 1667898396, 5576255601, 18642932177, 62328230082, 208379401186, 696665636518, 2329130179184, 7786871066006

Offset

1,1

Comments

Column 2 of A220461

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 6*a(n-1) -11*a(n-2) +10*a(n-3) -11*a(n-4) +7*a(n-5) -22*a(n-6) +61*a(n-7) -101*a(n-8) +159*a(n-9) -166*a(n-10) +159*a(n-11) -137*a(n-12) +189*a(n-13) -246*a(n-14) +239*a(n-15) -183*a(n-16) +96*a(n-17) -60*a(n-18) +193*a(n-19) -214*a(n-20) +187*a(n-21) -199*a(n-22) +29*a(n-23) -105*a(n-24) +20*a(n-25) -37*a(n-26) +13*a(n-27) -8*a(n-28) +4*a(n-29) for n>34

Example

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

Crossrefs

Sequence in context: A134246 A254867 A305492 * A071298 A152104 A047035

Adjacent sequences: A220453 A220454 A220455 * A220457 A220458 A220459

Keyword

nonn

Author

R. H. Hardin Dec 15 2012

Status

approved