A263870 Number of (n+1)X(5+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits, and rows and columns lexicographically nondecreasing.

4, 4, 14, 16, 61, 93, 494, 975, 4917, 10340, 41366, 85816, 280438, 562456, 1574783, 3040270, 7560914, 14059280, 31856173, 57181978, 120205886, 208862596, 412782291, 696193791, 1306513751, 2144538358, 3851037496, 6166629823

Offset

1,1

Comments

Column 5 of A263873.

Links

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

Formula

Empirical: a(n) = a(n-1) +18*a(n-2) -18*a(n-3) -153*a(n-4) +153*a(n-5) +816*a(n-6) -816*a(n-7) -3060*a(n-8) +3060*a(n-9) +8568*a(n-10) -8568*a(n-11) -18564*a(n-12) +18564*a(n-13) +31824*a(n-14) -31824*a(n-15) -43758*a(n-16) +43758*a(n-17) +48620*a(n-18) -48620*a(n-19) -43758*a(n-20) +43758*a(n-21) +31824*a(n-22) -31824*a(n-23) -18564*a(n-24) +18564*a(n-25) +8568*a(n-26) -8568*a(n-27) -3060*a(n-28) +3060*a(n-29) +816*a(n-30) -816*a(n-31) -153*a(n-32) +153*a(n-33) +18*a(n-34) -18*a(n-35) -a(n-36) +a(n-37)

Example

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

Crossrefs

Cf. A263873.

Sequence in context: A339319 A347428 A361801 * A263796 A263871 A326982

Adjacent sequences: A263867 A263868 A263869 * A263871 A263872 A263873

Keyword

nonn

Author

R. H. Hardin, Oct 28 2015

Status

approved