A255228 T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with no 3x3 subblock diagonal sum 0 and no antidiagonal sum 0 and no row sum 2 and no column sum 2

23, 22, 22, 31, 28, 31, 43, 37, 37, 43, 61, 49, 46, 49, 61, 88, 67, 58, 58, 67, 88, 127, 94, 76, 70, 76, 94, 127, 184, 133, 103, 88, 88, 103, 133, 184, 268, 190, 142, 115, 106, 115, 142, 190, 268, 391, 274, 199, 154, 133, 133, 154, 199, 274, 391, 571, 397, 283, 211, 172

Offset

1,1

Comments

Table starts

..23..22..31..43..61..88.127.184.268.391.571..835.1222.1789.2620.3838.5623.8239

..22..28..37..49..67..94.133.190.274.397.577..841.1228.1795.2626.3844.5629.8245

..31..37..46..58..76.103.142.199.283.406.586..850.1237.1804.2635.3853.5638.8254

..43..49..58..70..88.115.154.211.295.418.598..862.1249.1816.2647.3865.5650.8266

..61..67..76..88.106.133.172.229.313.436.616..880.1267.1834.2665.3883.5668.8284

..88..94.103.115.133.160.199.256.340.463.643..907.1294.1861.2692.3910.5695.8311

.127.133.142.154.172.199.238.295.379.502.682..946.1333.1900.2731.3949.5734.8350

.184.190.199.211.229.256.295.352.436.559.739.1003.1390.1957.2788.4006.5791.8407

.268.274.283.295.313.340.379.436.520.643.823.1087.1474.2041.2872.4090.5875.8491

.391.397.406.418.436.463.502.559.643.766.946.1210.1597.2164.2995.4213.5998.8614

Links

R. H. Hardin, Table of n, a(n) for n = 1..1860

Formula

Empirical for diagonal:

a(n) = 2*a(n-1) -a(n-2) +a(n-3) -a(n-4) for n>5

Empirical for column k:

k=1: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -a(n-4) for n>5

k=2-7: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -a(n-4)

Example

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

Crossrefs

Sequence in context: A022979 A023465 A004464 * A374669 A255221 A072135

Adjacent sequences: A255225 A255226 A255227 * A255229 A255230 A255231

Keyword

nonn,tabl

Author

R. H. Hardin, Feb 17 2015

Status

approved