A233897 Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having the sum of the squares of all six edge and diagonal differences equal to 35.

144, 656, 2688, 12288, 51200, 233984, 987136, 4503552, 19185664, 87351296, 375062528, 1704296448, 7364935680, 33408548864, 145134452736, 657383227392, 2868195098624, 12975463202816, 56813072416768, 256757263761408

Offset

1,1

Links

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

Formula

Empirical: a(n) = 44*a(n-2) - 608*a(n-4) + 2560*a(n-6).

Empirical g.f.: 16*x*(9 + 41*x - 228*x^2 - 1036*x^3 + 1280*x^4 + 5760*x^5) / ((1 - 4*x)*(1 + 4*x)*(1 - 8*x^2)*(1 - 20*x^2)). - Colin Barker, Oct 12 2018

Example

Some solutions for n=5:
..4..1....3..4....1..3....2..1....5..4....1..4....3..1....2..3....1..5....1..3
..0..2....5..1....2..5....3..5....2..6....3..5....5..4....0..4....4..3....5..4
..1..4....4..3....3..1....2..1....4..5....1..2....2..6....1..2....5..1....2..6
..5..3....0..2....4..5....5..3....1..3....3..5....4..3....3..5....3..2....4..3
..1..2....4..3....2..6....2..1....5..4....1..4....2..0....4..1....4..6....6..2
..5..3....0..2....5..4....4..0....2..6....0..2....1..4....5..3....5..2....4..3

Crossrefs

Column 1 of A233903.

Sequence in context: A204398 A204391 A233903 * A250428 A033696 A233653

Adjacent sequences: A233894 A233895 A233896 * A233898 A233899 A233900

Keyword

nonn

Author

R. H. Hardin, Dec 17 2013

Status

approved