A204635 Number of (n+2)X3 0..3 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..3 introduced in row major order

124, 405, 1781, 4246, 16855, 65096, 144255, 651750, 2480147, 6826114, 28519709, 102468425, 302547337, 1231849272, 4512654559, 14517240364, 56492934539, 205115926577, 698714375439, 2693352796243, 9877987196219, 34884036107922

Offset

1,1

Comments

Column 1 of A204642

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -14*a(n-2) +32*a(n-3) -178*a(n-4) +518*a(n-5) -1017*a(n-6) +609*a(n-7) -2461*a(n-8) +25287*a(n-9) -43874*a(n-10) +6054*a(n-11) -25095*a(n-12) +64297*a(n-13) +152172*a(n-14) -435728*a(n-15) +555156*a(n-16) -501972*a(n-17) +253956*a(n-18) +255660*a(n-19) -906516*a(n-20) +522900*a(n-21) +294048*a(n-22) +45792*a(n-23) -362448*a(n-24) +434592*a(n-25) -860544*a(n-26) +715392*a(n-27) -186624*a(n-28) for n>29

Example

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

Crossrefs

Sequence in context: A045250 A258931 A204642 * A102589 A189812 A230830

Adjacent sequences: A204632 A204633 A204634 * A204636 A204637 A204638

Keyword

nonn

Author

R. H. Hardin Jan 17 2012

Status

approved