A256765 Number of (n+2)X(2+2) 0..1 arrays with no 3x3 subblock diagonal sum less than the antidiagonal sum

1936, 14641, 81796, 456976, 2196324, 10556001, 46785600, 207360000, 878529600, 3722098081, 15374512036, 63506016016, 258598692676, 1053022816561, 4253774251024, 17183478927616, 69105769488144, 277918540050321

Offset

1,1

Comments

Column 2 of A256771

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +30*a(n-2) -230*a(n-3) -312*a(n-4) +3822*a(n-5) +534*a(n-6) -36354*a(n-7) +17505*a(n-8) +220020*a(n-9) -193524*a(n-10) -889056*a(n-11) +1056104*a(n-12) +2438976*a(n-13) -3613728*a(n-14) -4492832*a(n-15) +8271888*a(n-16) +5259072*a(n-17) -12868032*a(n-18) -3211008*a(n-19) +13425408*a(n-20) -181248*a(n-21) -8979456*a(n-22) +1806336*a(n-23) +3473408*a(n-24) -1179648*a(n-25) -589824*a(n-26) +262144*a(n-27)

Example

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

Crossrefs

Cf. A256771

Sequence in context: A340843 A270265 A237010 * A264109 A188369 A185570

Adjacent sequences: A256762 A256763 A256764 * A256766 A256767 A256768

Keyword

nonn

Author

R. H. Hardin, Apr 09 2015

Status

approved