A262850 Number of (1+2)X(n+2) 0..1 arrays with each row divisible by 7 and column not divisible by 7, read as a binary number with top and left being the most significant bits.

6, 6, 12, 318, 900, 4536, 34782, 178926, 1042284, 6538206, 38160540, 227814120, 1377960126, 8227422006, 49321272972, 296370593598, 1776644188020, 10658199015576, 63967089528222, 383739633130686, 2302372435469484

Offset: 1

Author

R. H. Hardin, Oct 03 2015

Keywords

• nonn

Comments

Row 1 of A262849.

Examples

			Some solutions for n=4
..1..0..1..0..1..0....1..1..1..0..0..0....1..0..1..0..1..0....0..1..0..1..0..1
..0..0..0..0..0..0....0..0..0..0..0..0....0..1..0..1..0..1....0..0..0..0..0..0
..1..1..1..1..1..1....0..0..0..1..1..1....0..1..1..1..0..0....1..1..1..1..1..1
		

Links

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

Crossrefs

Cf. A262849.

Formula

Empirical: a(n) = 6*a(n-1) +72*a(n-3) -432*a(n-4) -1270*a(n-6) +7620*a(n-7) -2880*a(n-9) +17280*a(n-10) +113591*a(n-12) -681546*a(n-13) +115128*a(n-15) -690768*a(n-16)