A263796 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 nonincreasing

4, 4, 14, 17, 61, 130, 494, 1435, 4917, 13962, 41366, 107284, 280438, 666212, 1574783, 3468753, 7560914, 15618901, 31856173, 62297164, 120205886, 224230549, 412782291, 739028663, 1306513751, 2256420867, 3851037496, 6442700456

Offset

1,1

Comments

Column 5 of A263799

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=5
..1..1..1..1..0..0....1..1..1..1..0..0....1..1..1..1..0..0....1..1..1..1..1..1
..1..1..1..1..0..0....1..1..0..0..1..1....1..1..0..0..0..0....1..1..1..1..1..1
..1..1..1..1..0..0....1..0..1..0..1..0....1..0..1..0..1..0....1..1..1..1..0..0
..1..1..1..1..0..0....1..0..0..1..0..0....1..0..0..1..1..1....1..1..1..1..0..0
..1..1..0..0..1..1....0..1..1..0..1..1....0..0..1..0..0..1....1..1..0..0..0..0
..1..1..0..0..1..1....0..1..0..0..1..0....0..0..0..0..0..0....1..1..0..0..0..0

Crossrefs

Cf. A263799

Sequence in context: A347428 A361801 A263870 * A263871 A326982 A263797

Adjacent sequences: A263793 A263794 A263795 * A263797 A263798 A263799

Keyword

nonn

Author

R. H. Hardin, Oct 26 2015

Status

approved