A297657 Number of 4Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 3 neighboring 1s.

1, 126, 1421, 11024, 131044, 1580681, 16899640, 184447765, 2071914854, 22993996808, 253857329257, 2815072088290, 31231596904276, 346040351074271, 3834662231710946, 42507894984837013, 471153783855939918

Offset

1,2

Comments

Row 4 of A297654.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +15*a(n-2) +372*a(n-3) +1025*a(n-4) -46*a(n-5) -4101*a(n-6) -34244*a(n-7) -94085*a(n-8) -21654*a(n-9) +165356*a(n-10) +639904*a(n-11) +1471523*a(n-12) -895908*a(n-13) -4864047*a(n-14) -1270214*a(n-15) +3721117*a(n-16) +3725224*a(n-17) +1517589*a(n-18) -2895666*a(n-19) +611461*a(n-20) -1569477*a(n-21) -5436112*a(n-22) +6015995*a(n-23) -1131454*a(n-24) -3262066*a(n-25) +5806854*a(n-26) -3112355*a(n-27) -927930*a(n-28) +2386399*a(n-29) -1228290*a(n-30) -18124*a(n-31) +313018*a(n-32) -154300*a(n-33) +36726*a(n-34) +142*a(n-35) -2108*a(n-36) +652*a(n-37) +4*a(n-38)

Example

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

Crossrefs

Cf. A297654.

Sequence in context: A194717 A002953 A216588 * A027805 A027814 A109146

Adjacent sequences: A297654 A297655 A297656 * A297658 A297659 A297660

Keyword

nonn

Author

R. H. Hardin, Jan 02 2018

Status

approved