A239188 Number of n X 2 0..4 arrays with no element equal to the sum of elements to its left or the sum of elements above it, modulo 5.

12, 120, 1276, 13128, 136684, 1416192, 14700364, 152485288, 1582134540, 16414034784, 170295680876, 1766793480968, 18330328103340, 190175177307584, 1973048416742796, 20470174034391656, 212375968504319052

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) + 50*a(n-2) - 26*a(n-3) - 253*a(n-4) + 240*a(n-5) + 416*a(n-6) - 624*a(n-7).

Empirical g.f.: 4*x*(3 + 12*x - 11*x^2 - 54*x^3 + 68*x^4 + 86*x^5 - 156*x^6) / (1 - 6*x - 50*x^2 + 26*x^3 + 253*x^4 - 240*x^5 - 416*x^6 + 624*x^7). - Colin Barker, Oct 25 2018

Example

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

Crossrefs

Column 2 of A239194.

Sequence in context: A361573 A129064 A120585 * A200163 A012565 A012621

Adjacent sequences: A239185 A239186 A239187 * A239189 A239190 A239191

Keyword

nonn

Author

R. H. Hardin, Mar 11 2014

Status

approved