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

1,1

Comments

Row 4 of A262759.

Links

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

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) +19434375*a(n-9) -97171875*a(n-10) +485859375*a(n-11) -1589281250*a(n-12) -453750000*a(n-13) +2268750000*a(n-14) -11343750000*a(n-15) +37812500000*a(n-16)

Example

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

Crossrefs

Cf. A262759.

Sequence in context: A207897 A207657 A305668 * A134556 A207449 A208551

Adjacent sequences: A262758 A262759 A262760 * A262762 A262763 A262764

Keyword

nonn

Author

R. H. Hardin, Sep 30 2015

Status

approved