A257427 Number of (2+2)X(n+2) 0..1 arrays with every 3X3 subblock diagonal sum plus antidiagonal minimum nondecreasing horizontally, vertically and ne-to-sw antidiagonally

2616, 7652, 27244, 103575, 367929, 1246585, 4137316, 13275095, 41621545, 128299778, 389217704, 1165610625, 3456006395, 10159155410, 29647440717, 85997742083, 248174114409, 713062049952, 2041229428915, 5824856350604

Offset

1,1

Comments

Row 2 of A257426

Links

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

Formula

Empirical: a(n) = 12*a(n-1) -59*a(n-2) +149*a(n-3) -183*a(n-4) +4*a(n-5) +387*a(n-6) -898*a(n-7) +1676*a(n-8) -2700*a(n-9) +2747*a(n-10) -402*a(n-11) -2768*a(n-12) +3997*a(n-13) -6569*a(n-14) +16618*a(n-15) -28520*a(n-16) +26140*a(n-17) -1034*a(n-18) -40700*a(n-19) +77375*a(n-20) -78495*a(n-21) +39296*a(n-22) +12893*a(n-23) -55386*a(n-24) +75767*a(n-25) -68529*a(n-26) +44593*a(n-27) -16089*a(n-28) -9340*a(n-29) +25380*a(n-30) -34396*a(n-31) +37828*a(n-32) -33880*a(n-33) +23505*a(n-34) -6240*a(n-35) -12114*a(n-36) +20302*a(n-37) -17424*a(n-38) +10344*a(n-39) -3748*a(n-40) -171*a(n-41) +1387*a(n-42) -1676*a(n-43) +1939*a(n-44) -1745*a(n-45) +1052*a(n-46) -401*a(n-47) +51*a(n-48) +92*a(n-49) -137*a(n-50) +116*a(n-51) -60*a(n-52) +17*a(n-53) -2*a(n-54) for n>66

Example

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

Crossrefs

Cf. A257426

Sequence in context: A252341 A235777 A235557 * A257420 A254236 A252440

Adjacent sequences: A257424 A257425 A257426 * A257428 A257429 A257430

Keyword

nonn

Author

R. H. Hardin, Apr 22 2015

Status

approved