A204475 Number of (n+2)X3 0..3 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..3 introduced in row major order

80, 307, 1157, 1899, 7191, 24718, 70726, 277992, 996500, 3558732, 13565616, 51046854, 192347648, 730397369, 2770971357, 10530282255, 40019308588, 152140400520, 578605689115, 2200549646588, 8369694858448, 31835066870337

Offset

1,1

Comments

Column 1 of A204483

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -21*a(n-2) +22*a(n-3) -22*a(n-4) +60*a(n-5) -12*a(n-6) -448*a(n-7) +1866*a(n-8) -6498*a(n-9) +15684*a(n-10) -22888*a(n-11) +31417*a(n-12) -57462*a(n-13) +52230*a(n-14) +113688*a(n-15) -424149*a(n-16) +557158*a(n-17) -411880*a(n-18) +403956*a(n-19) -471132*a(n-20) -17430*a(n-21) +839565*a(n-22) -1046718*a(n-23) +545742*a(n-24) -113292*a(n-25) +131571*a(n-26) -347004*a(n-27) +373977*a(n-28) -80190*a(n-29) -271188*a(n-30) +354294*a(n-31) -190269*a(n-32) +39366*a(n-33)

Example

Some solutions for n=3
..0..0..1....0..0..0....0..1..0....0..0..0....0..1..2....0..1..0....0..0..0
..1..1..1....1..1..1....0..2..0....1..1..1....0..0..2....0..0..1....1..0..0
..1..1..1....1..1..1....0..0..0....2..2..2....0..0..0....0..0..0....1..1..0
..1..2..2....2..1..3....2..3..0....2..2..2....3..0..0....0..0..2....1..1..1
..1..1..1....3..1..1....0..0..0....2..1..3....2..3..0....0..0..1....0..1..1

Crossrefs

Sequence in context: A194646 A057441 A204483 * A157953 A233958 A233951

Adjacent sequences: A204472 A204473 A204474 * A204476 A204477 A204478

Keyword

nonn

Author

R. H. Hardin Jan 15 2012

Status

approved