A262846 Number of (n+2)X(4+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.

318, 3181, 37635, 420654, 3896365, 39348387, 417279054, 3999504445, 39913429587, 409857534030, 4017392736541, 40104536998707, 405732145282158, 4021339824862381, 40178930760566115, 403823141865184494

Offset: 1

Author

R. H. Hardin, Oct 03 2015

Keywords

• nonn

Comments

Column 4 of A262849.

Examples

			Some solutions for n=3
..0..1..1..1..0..0....1..1..1..0..0..0....1..0..0..0..1..1....0..0..0..0..0..0
..1..0..0..0..1..1....0..0..0..1..1..1....1..0..1..0..1..0....1..0..0..0..1..1
..1..1..1..1..1..1....0..0..0..0..0..0....1..1..0..0..0..1....0..1..1..1..0..0
..0..1..0..1..0..1....0..0..1..1..1..0....1..0..0..0..1..1....0..1..0..1..0..1
..1..1..0..0..0..1....0..0..0..0..0..0....0..1..1..1..0..0....1..0..1..0..1..0
		

Links

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

Crossrefs

Cf. A262849.

Formula

Empirical: a(n) = 13*a(n-1) -30*a(n-2) +775*a(n-3) -10075*a(n-4) +23250*a(n-5) -187265*a(n-6) +2434445*a(n-7) -5617950*a(n-8) [phone]*a(n-9) -238880915*a(n-10) [phone]*a(n-11) -585288123*a(n-12) [phone]*a(n-13) -17558643690*a(n-14) -12851058675*a(n-15) [phone]*a(n-16) -385531760250*a(n-17) [phone]*a(n-18) -9852975349945*a(n-19) [phone]*a(n-20) -1115961555955*a(n-21) [phone]*a(n-22) -33478846678650*a(n-23) -69403913471776*a(n-24) [phone]*a(n-25) -2082117404153280*a(n-26) -67517783528000*a(n-27) [phone]*a(n-28) -2025533505840000*a(n-29)