A301953 Number of 4Xn 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

0, 13, 83, 947, 9084, 98839, 1029960, 10839822, 113808922, 1195709047, 12560090528, 131941626696, 1386007798945, 14559641418947, 152945061251677, 1606646289820269, 16877382303769959, 177292310984136323

Offset: 1

Author

R. H. Hardin, Mar 29 2018

Keywords

• nonn

Comments

Row 4 of A301951.

Examples

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

Links

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

Crossrefs

Cf. A301951.

Formula

Empirical: a(n) = 7*a(n-1) +51*a(n-2) -82*a(n-3) -768*a(n-4) +138*a(n-5) +5682*a(n-6) +2208*a(n-7) -27378*a(n-8) -19646*a(n-9) +108234*a(n-10) +113576*a(n-11) -351398*a(n-12) -518894*a(n-13) +797178*a(n-14) +1775528*a(n-15) -1138958*a(n-16) -4727986*a(n-17) +650274*a(n-18) [phone]*a(n-19) +3872450*a(n-20) -18087578*a(n-21) -17435194*a(n-22) [phone]*a(n-23) [phone]*a(n-24) -5946897*a(n-25) -6975733*a(n-26) -3960654*a(n-27) +1318878*a(n-28) +806952*a(n-29) +364004*a(n-30) -117352*a(n-31) -127336*a(n-32) +19920*a(n-33) +21504*a(n-34) +1728*a(n-35) -3456*a(n-36) for n>40