A251854 Number of (n+2) X (1+2) 0..3 arrays with no row, column, diagonal or antidiagonal in any 3 X 3 subblock summing to 4 or more.

2506, 23664, 245388, 2525037, 25675786, 261035198, 2662774377, 27176100008, 277114175198, 2825487281379, 28815310648166, 293871957879238, 2996892351232026, 30562142295918712, 311674542590050172

Offset

1,1

Comments

Column 1 of A251858.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +237*a(n-3) +49*a(n-4) -338*a(n-5) -9750*a(n-6) -15248*a(n-7) +48037*a(n-8) +240021*a(n-9) +97139*a(n-10) -1418721*a(n-11) -1982135*a(n-12) +1686391*a(n-13) +10565620*a(n-14) +7309644*a(n-15) -9917535*a(n-16) -31045859*a(n-17) -25797927*a(n-18) +58704615*a(n-19) +26206302*a(n-20) -5056046*a(n-21) -141810900*a(n-22) -241551457*a(n-23) +154823660*a(n-24) +60706708*a(n-25) -5551687*a(n-26) +242672037*a(n-27) -67918061*a(n-28) -56779807*a(n-29) +191693446*a(n-30) -275509590*a(n-31) +173315508*a(n-32) -137261046*a(n-33) +74795940*a(n-34) -153762581*a(n-35) +86481806*a(n-36) -30625610*a(n-37) +86810871*a(n-38) -65005646*a(n-39) +34966690*a(n-40) +1570442*a(n-41) -25820357*a(n-42) -3556821*a(n-43) +48687607*a(n-44) -1688437*a(n-45) -16066648*a(n-46) -5211738*a(n-47) +2384118*a(n-48) -1274406*a(n-49) +371162*a(n-50) +456968*a(n-51) +472070*a(n-52) -78856*a(n-53) +7744*a(n-54) for n>60.

Example

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

Crossrefs

Cf. A251858.

Sequence in context: A205274 A234790 A251858 * A203055 A031621 A212400

Adjacent sequences: A251851 A251852 A251853 * A251855 A251856 A251857

Keyword

nonn

Author

R. H. Hardin, Dec 09 2014

Status

approved