A255796 Number of (n+2) X (3+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 1 and no antidiagonal sum 2 and no row sum 0 and no column sum 3.

210, 178, 158, 198, 256, 258, 329, 344, 392, 456, 597, 638, 805, 892, 1028, 1144, 1493, 1622, 2021, 2268, 2636, 2864, 3713, 4038, 4981, 5580, 6524, 6992, 9009, 9766, 11957, 13324, 15644, 16624, 21313, 23014, 28021, 31052, 36572, 38640, 49345, 53094, 64373

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-6) - 8*a(n-12) + 4*a(n-18) for n>20.

Empirical g.f.: x*(210 + 178*x + 158*x^2 + 198*x^3 + 256*x^4 + 258*x^5 - 721*x^6 - 546*x^7 - 398*x^8 - 534*x^9 - 683*x^10 - 652*x^11 + 840*x^12 + 596*x^13 + 332*x^14 + 448*x^15 + 556*x^16 + 496*x^17 - 212*x^18 - 152*x^19) / ((1 - x)*(1 + x)*(1 - x + x^2)*(1 + x + x^2)*(1 - 2*x^6)^2). - Colin Barker, Dec 19 2018

Example

Some solutions for n=4:
..1..1..1..0..1....0..0..1..1..0....0..1..1..0..1....1..0..0..1..1
..0..1..0..1..0....0..1..0..0..1....0..1..0..1..0....0..1..0..1..0
..1..0..1..1..0....1..0..1..0..1....1..0..1..1..0....0..0..1..0..1
..0..1..0..0..1....1..0..0..1..0....0..1..0..0..1....0..1..0..1..0
..1..0..1..0..1....0..1..1..0..0....1..0..1..0..1....1..0..1..0..1
..1..0..0..1..0....0..1..1..1..0....1..0..0..1..0....1..1..0..1..0

Crossrefs

Column 3 of A255801.

Sequence in context: A259916 A050516 A100670 * A220441 A025392 A025383

Adjacent sequences: A255793 A255794 A255795 * A255797 A255798 A255799

Keyword

nonn

Author

R. H. Hardin, Mar 06 2015

Status

approved