A241307 Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4

5, 6, 15, 25, 40, 89, 121, 237, 390, 682, 1250, 2069, 3698, 6352, 11013, 19408, 33478, 58524, 101542, 176797, 307761, 535313, 932344, 1620570, 2821554, 4908976, 8540842, 14866293, 25861744, 45006289, 78311151, 136266311, 237120535

Offset

1,1

Comments

Row 2 of A241306

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +3*a(n-3) -a(n-4) -a(n-5) +2*a(n-6) -10*a(n-8) -7*a(n-9) +8*a(n-10) +5*a(n-11) -3*a(n-12) -7*a(n-13) +7*a(n-14) for n>20

Example

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

Crossrefs

Sequence in context: A227066 A115908 A247962 * A185876 A356496 A091020

Adjacent sequences: A241304 A241305 A241306 * A241308 A241309 A241310

Keyword

nonn

Author

R. H. Hardin, Apr 18 2014

Status

approved