A297804 Number of 4Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 5 neighboring 1s.

1, 7, 108, 422, 2195, 16006, 115773, 738989, 4837309, 32657747, 219582492, 1461795891, 9752902800, 65247730522, 436241303976, 2914287342877, 19473374657852, 130152068036883, 869816886352210, 5812664008298957

Offset

1,2

Comments

Row 4 of A297802.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +2*a(n-2) +19*a(n-3) +170*a(n-4) -1100*a(n-5) -1037*a(n-6) +1524*a(n-7) -7143*a(n-8) +44464*a(n-9) +70155*a(n-10) -178747*a(n-11) -49015*a(n-12) -56143*a(n-13) -605420*a(n-14) +1629247*a(n-15) +789405*a(n-16) -3542455*a(n-17) +1821929*a(n-18) +697014*a(n-19) +1736175*a(n-20) +6611206*a(n-21) -24159699*a(n-22) -6040442*a(n-23) +22645180*a(n-24) -8302835*a(n-25) +45128805*a(n-26) +8483674*a(n-27) -57414625*a(n-28) +51319534*a(n-29) -50987530*a(n-30) -122886914*a(n-31) +26911552*a(n-32) -56579692*a(n-33) -32032745*a(n-34) +210015730*a(n-35) +108215538*a(n-36) +41225268*a(n-37) +191116457*a(n-38) -78974*a(n-39) -97822681*a(n-40) -9791615*a(n-41) -104614992*a(n-42) -103358060*a(n-43) -20219044*a(n-44) -28055103*a(n-45) -51562*a(n-46) +5393515*a(n-47) +7808415*a(n-48) +1717135*a(n-49) -1385069*a(n-50) +1569214*a(n-51) -1224958*a(n-52) +22674*a(n-53) -36312*a(n-54) +21984*a(n-55)

Example

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

Crossrefs

Cf. A297802.

Sequence in context: A367157 A197447 A202780 * A218819 A033516 A130629

Adjacent sequences: A297801 A297802 A297803 * A297805 A297806 A297807

Keyword

nonn

Author

R. H. Hardin, Jan 06 2018

Status

approved