A186832 Number of (n+2)X3 binary arrays with 3X3 subblock sums nondecreasing rightwards and downwards.

512, 2688, 14112, 74088, 324576, 1421952, 6229504, 24748736, 98322424, 390617891, 1462011696, 5472043776, 20480864256, 73689191424, 265130263296, 953926283584, 3338160566528, 11681527346176, 40878225723392, 140146288207104

Offset

1,1

Comments

Column 1 of A186840

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=8*a(n-1)-22*a(n-2)+128*a(n-3)-841*a(n-4)+2288*a(n-5)-6994*a(n-6)+36920*a(n-7)-98956*a(n-8)+214920*a(n-9)-896226*a(n-10)+2353296*a(n-11)-4131639*a(n-12)+13477968*a(n-13)-34416954*a(n-14)+52411320*a(n-15)-133004079*a(n-16)+327042144*a(n-17)-450989532*a(n-18)+887520240*a(n-19)-2072758248*a(n-20)+2662560720*a(n-21)-4058905788*a(n-22)+8830137888*a(n-23)-10773330399*a(n-24)+12735950760*a(n-25)-25089959466*a(n-26)+29476316016*a(n-27)-27107683479*a(n-28)+46319925168*a(n-29)-52921249074*a(n-30)+38072433240*a(n-31)-52589275596*a(n-32)+58862405160*a(n-33)-33452085186*a(n-34)+32830299216*a(n-35)-36202292361*a(n-36)+16529940864*a(n-37)-8523250758*a(n-38)+9298091736*a(n-39)-3486784401*a(n-40)

Example

Some solutions for 4X3
..0..1..0....0..1..1....1..0..0....0..0..0....1..0..0....0..0..0....1..1..0
..1..1..1....1..0..1....0..0..1....0..0..0....1..1..0....1..0..1....0..1..1
..1..0..0....1..0..1....1..1..0....1..1..1....0..1..1....0..1..0....0..1..1
..0..1..1....1..0..1....0..1..0....1..1..1....0..1..0....1..0..1....1..0..1

Crossrefs

Sequence in context: A254991 A186840 A224643 * A254553 A254483 A254476

Adjacent sequences: A186829 A186830 A186831 * A186833 A186834 A186835

Keyword

nonn

Author

R. H. Hardin, Feb 27 2011

Status

approved