A241356 T(n,k) = Number of n X k 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 one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.
2, 2, 3, 4, 3, 4, 6, 9, 3, 7, 8, 17, 19, 4, 10, 14, 23, 51, 55, 5, 15, 20, 53, 61, 128, 72, 5, 24, 30, 103, 230, 228, 248, 124, 7, 35, 48, 160, 641, 1721, 615, 624, 243, 8, 54, 70, 344, 960, 5663, 6307, 2062, 1323, 370, 9, 83, 108, 643, 3746, 11909, 32942, 35880, 6380, 2715
Offset: 1
Examples
Some solutions for n=4, k=4 ..3..2..3..3....3..2..3..3....3..2..3..3....3..2..3..3....3..2..3..3 ..3..1..1..2....3..1..1..3....3..1..2..1....3..1..2..1....3..1..2..1 ..2..1..0..1....2..1..0..1....2..3..0..3....2..3..3..3....2..3..0..3 ..3..0..2..2....3..2..3..2....3..0..1..3....2..1..0..1....3..2..0..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..143
Formula
Empirical for column k:
k=1: a(n) = a(n-2) +2*a(n-3).
k=2: a(n) = a(n-3) +a(n-5).
k=3: [order 68] for n > 85.
Empirical for row n:
n=1: a(n) = a(n-2) +2*a(n-3).
n=2: [order 17] for n > 20.
Comments