A241436 Number of 2Xn 0..3 arrays with no element equal to one 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 one plus the sum of the elements antidiagonally to its northeast, modulo 4

3, 5, 10, 21, 45, 88, 181, 378, 710, 1460, 2973, 5668, 11567, 23202, 45182, 91386, 182056, 358886, 721278, 1433814, 2843343, 5691577, 11312714, 22494505, 44919750, 89325211, 177819368, 354608529, 705515901, 1405063399, 2799954077, 5572860402

Offset

1,1

Comments

Row 2 of A241435

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +8*a(n-3) -a(n-4) -10*a(n-5) -18*a(n-6) +8*a(n-7) +20*a(n-8) +20*a(n-9) -24*a(n-10) -22*a(n-11) -a(n-12) +32*a(n-13) +8*a(n-14) -3*a(n-15) -12*a(n-16) +4*a(n-17) -5*a(n-18) -4*a(n-20) -3*a(n-21) +2*a(n-22) for n>24

Example

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

Crossrefs

Sequence in context: A024424 A293321 A284237 * A018107 A360882 A053709

Adjacent sequences: A241433 A241434 A241435 * A241437 A241438 A241439

Keyword

nonn

Author

R. H. Hardin, Apr 22 2014

Status

approved