A297317 Number of 4Xn 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 or 2 neighboring 1s.

1, 65, 609, 3808, 35476, 340825, 2997197, 26513027, 237701708, 2127406714, 19008671433, 169867295652, 1518292533694, 13571135299252, 121300487637606, 1084181857884980, 9690470338269840, 86614217136138558, 774163716085023913

Offset

1,2

Comments

Row 4 of A297314.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -19*a(n-2) +241*a(n-3) -214*a(n-4) +2642*a(n-5) -4441*a(n-6) +10173*a(n-7) -44273*a(n-8) +27691*a(n-9) -123086*a(n-10) +338644*a(n-11) +977891*a(n-12) -2407823*a(n-13) -1722701*a(n-14) +5420139*a(n-15) +181351*a(n-16) -530670*a(n-17) -5094160*a(n-18) -11451388*a(n-19) +23975138*a(n-20) +13834285*a(n-21) -45414081*a(n-22) +22470502*a(n-23) -4685760*a(n-24) -10494413*a(n-25) +68713200*a(n-26) -90955823*a(n-27) +1979872*a(n-28) +123075762*a(n-29) -166311052*a(n-30) +114905974*a(n-31) -28056285*a(n-32) -23893428*a(n-33) +23876735*a(n-34) -10891063*a(n-35) -4771775*a(n-36) +5539152*a(n-37) +1564374*a(n-38) -2623482*a(n-39) +3267984*a(n-40) -1046749*a(n-41) +32122*a(n-42) +232950*a(n-43) -239978*a(n-44) +59114*a(n-45) +11836*a(n-46) -17936*a(n-47) -14104*a(n-48) +7504*a(n-49) -7357*a(n-50) +5254*a(n-51) +506*a(n-52) -959*a(n-53) +335*a(n-54) -181*a(n-55) +67*a(n-56) +25*a(n-57) -2*a(n-58) -6*a(n-59) -2*a(n-60) +a(n-61)

Example

Some solutions for n=5
..1..1..1..0..0. .0..0..0..1..1. .0..1..1..0..1. .1..1..1..0..1
..0..1..1..0..1. .0..1..1..0..0. .0..1..1..1..0. .0..0..0..1..0
..0..1..0..1..0. .0..0..1..0..0. .0..0..0..0..1. .0..1..1..0..0
..0..0..1..1..0. .0..1..0..0..0. .1..1..0..1..1. .1..0..1..1..0

Crossrefs

Cf. A297314.

Sequence in context: A276963 A338413 A211404 * A224099 A220229 A200890

Adjacent sequences: A297314 A297315 A297316 * A297318 A297319 A297320

Keyword

nonn

Author

R. H. Hardin, Dec 28 2017

Status

approved