A297803 Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 5 neighboring 1s.

1, 4, 37, 100, 293, 1320, 6215, 24879, 99567, 422308, 1804127, 7556513, 31570236, 132859288, 559967531, 2354250563, 9891690637, 41598759825, 174990998789, 735895232858, 3094315102349, 13012504569964, 54724162019621

Offset: 1

Author

R. H. Hardin, Jan 06 2018

Keywords

• nonn

Comments

Row 3 of A297802.

Examples

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

Links

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

Crossrefs

Cf. A297802.

Formula

Empirical: a(n) = 4*a(n-1) -4*a(n-2) +19*a(n-3) +32*a(n-4) -91*a(n-5) -260*a(n-7) -403*a(n-8) +590*a(n-9) +467*a(n-10) +69*a(n-11) -380*a(n-12) -48*a(n-13) -115*a(n-14) +216*a(n-15) +359*a(n-16) +36*a(n-17) -221*a(n-18) -89*a(n-19) -5*a(n-20) +12*a(n-21)