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

1,2

Comments

Row 4 of A301951.

Links

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

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) +10582688*a(n-19) +3872450*a(n-20) -18087578*a(n-21) -17435194*a(n-22) +17909432*a(n-23) +24700399*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

Example

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

Crossrefs

Cf. A301951.

Sequence in context: A142085 A163688 A274398 * A321589 A225129 A297207

Adjacent sequences: A301950 A301951 A301952 * A301954 A301955 A301956

Keyword

nonn

Author

R. H. Hardin, Mar 29 2018

Status

approved