A296401 Number of nX4 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 2 or 3 neighboring 1s.

1, 17, 82, 444, 2868, 17783, 110554, 688248, 4288144, 26711200, 166398828, 1036671655, 6458139283, 40233032157, 250644098773, 1561462216313, 9727606977107, 60601079306268, 377532856173261, 2351955727736811

Offset

1,2

Comments

Column 4 of A296405.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -16*a(n-2) +43*a(n-3) -102*a(n-4) +267*a(n-5) -817*a(n-6) +1830*a(n-7) -4624*a(n-8) +9499*a(n-9) -17109*a(n-10) +24730*a(n-11) -21057*a(n-12) +1857*a(n-13) +28556*a(n-14) -37532*a(n-15) -9440*a(n-16) +101047*a(n-17) -153831*a(n-18) +138481*a(n-19) -15861*a(n-20) +39904*a(n-21) -59825*a(n-22) +156866*a(n-23) -42732*a(n-24) -115477*a(n-25) +106150*a(n-26) +51973*a(n-27) -203188*a(n-28) +10225*a(n-29) +209569*a(n-30) -84500*a(n-31) -151819*a(n-32) +106213*a(n-33) +90190*a(n-34) -110390*a(n-35) -21187*a(n-36) +89775*a(n-37) -18535*a(n-38) -58132*a(n-39) +29618*a(n-40) +29689*a(n-41) -21678*a(n-42) -10902*a(n-43) +10317*a(n-44) +2864*a(n-45) -3289*a(n-46) -397*a(n-47) +584*a(n-48) -14*a(n-49) -53*a(n-50) +14*a(n-51) -a(n-52)

Example

Some solutions for n=7
..1..1..1..0. .1..1..0..0. .0..1..1..0. .0..1..1..0. .0..0..1..1
..1..0..1..1. .1..0..0..0. .0..1..0..0. .1..0..1..1. .1..1..0..1
..1..1..0..1. .1..0..1..1. .1..0..1..1. .1..1..0..1. .1..0..1..1
..0..1..0..1. .1..0..1..0. .1..1..0..1. .0..1..1..0. .1..1..0..1
..1..0..1..0. .1..0..0..0. .1..0..1..0. .0..0..1..0. .0..0..1..1
..1..1..0..0. .1..0..0..1. .0..1..0..1. .1..1..0..1. .0..1..0..0
..0..0..0..0. .1..1..1..1. .0..1..1..1. .1..0..1..1. .1..1..0..0

Crossrefs

Cf. A296405.

Sequence in context: A001159 A053820 A294288 * A259142 A142059 A343498

Adjacent sequences: A296398 A296399 A296400 * A296402 A296403 A296404

Keyword

nonn

Author

R. H. Hardin, Dec 11 2017

Status

approved