A262761 Number of (4+2)X(n+2) 0..1 arrays with each row divisible by 5 and each column divisible by 7, read as a binary number with top and left being the most significant bits.

10, 100, 319, 1645, 16450, 243220, 1614175, 15350125, 153501250, 1790228500, 15826009375, 157647278125, 1576472781250, 16543231412500, 159357016609375, 1592677865078125, 15926778650781250, 161625340977812500

Offset: 1

Author

R. H. Hardin, Sep 30 2015

Keywords

• nonn

Comments

Row 4 of A262759.

Examples

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

Links

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

Crossrefs

Cf. A262759.

Formula

Empirical: a(n) = 15*a(n-1) -75*a(n-2) +375*a(n-3) +2200*a(n-4) -51750*a(n-5) +258750*a(n-6) -1293750*a(n-7) +3016875*a(n-8) [phone]*a(n-9) -97171875*a(n-10) [phone]*a(n-11) -1589281250*a(n-12) -453750000*a(n-13) [phone]*a(n-14) -11343750000*a(n-15) [phone]*a(n-16)