A184472 1/6 the number of (n+2)X6 0..2 arrays with each 3X3 subblock containing one of one value, four of another, and four of the last

12339, 19119, 30681, 53739, 127689, 322275, 878625, 2967411, 9800745, 32238603, 121975089, 436928547, 1519783929, 5949509979, 21894837441, 77688357939, 307915900809, 1145251722315, 4096740213585, 16319916055011, 60974970119385

Offset

1,1

Comments

Column 4 of A184477

Links

R. H. Hardin, Table of n, a(n) for n = 1..106

Formula

Empirical: a(n)=6*a(n-1)-11*a(n-2)+129*a(n-3)-738*a(n-4)+1353*a(n-5)-6290*a(n-6)+33312*a(n-7)-61072*a(n-8)+155640*a(n-9)-733968*a(n-10)+1345608*a(n-11)-2177568*a(n-12)+8661600*a(n-13)-15879600*a(n-14)+18027792*a(n-15)-56197152*a(n-16)+103028112*a(n-17)-89177760*a(n-18)+197883648*a(n-19)-362786688*a(n-20)+256296960*a(n-21)-350479872*a(n-22)+642546432*a(n-23)-390790656*a(n-24)+241864704*a(n-25)-443418624*a(n-26)+241864704*a(n-27)

Example

Some solutions with a(1,1)=0 for 4X6
..0..2..1..1..2..2....0..2..1..0..2..0....0..1..1..0..1..0....0..0..2..0..2..1
..0..2..0..1..2..1....0..0..2..0..0..2....1..2..0..1..0..1....0..2..2..1..0..1
..0..2..2..1..2..0....2..2..0..2..2..1....1..0..0..1..2..0....1..0..2..0..0..1
..0..2..1..1..2..2....0..2..1..0..2..0....1..0..1..1..0..0....0..0..2..0..2..1

Crossrefs

Sequence in context: A321492 A237782 A248717 * A371833 A350153 A251949

Adjacent sequences: A184469 A184470 A184471 * A184473 A184474 A184475

Keyword

nonn

Author

R. H. Hardin Jan 15 2011

Status

approved