A241392 Number of nX2 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4

2, 5, 13, 28, 64, 142, 318, 726, 1634, 3695, 8363, 18904, 42787, 96771, 218940, 495514, 1121224, 2537388, 5742666, 12996786, 29415660, 66576728, 150686121, 341060866, 771951453, 1747237409, 3954724092, 8951198975, 20260385570, 45857968649

Offset

1,1

Comments

Column 2 of A241397

Links

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

Formula

Empirical: a(n) = 3*a(n-2) +10*a(n-3) +3*a(n-4) -12*a(n-5) -46*a(n-6) -36*a(n-7) +12*a(n-8) +107*a(n-9) +87*a(n-10) +2*a(n-11) -145*a(n-12) -138*a(n-13) -48*a(n-14) +147*a(n-15) +185*a(n-16) +89*a(n-17) -94*a(n-18) -210*a(n-19) -111*a(n-20) +40*a(n-21) +176*a(n-22) +85*a(n-23) +30*a(n-24) -77*a(n-25) -47*a(n-26) -57*a(n-27) +14*a(n-29) +21*a(n-30) +14*a(n-31) -3*a(n-32) +2*a(n-33) -5*a(n-34) +a(n-35) +2*a(n-36) +a(n-37) -a(n-38)

Example

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

Crossrefs

Sequence in context: A122491 A320933 A290194 * A319778 A354559 A002559

Adjacent sequences: A241389 A241390 A241391 * A241393 A241394 A241395

Keyword

nonn

Author

R. H. Hardin, Apr 20 2014

Status

approved