A241429 Number of n X 2 0..3 arrays with no element equal to one 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.

3, 5, 2, 3, 5, 6, 9, 10, 15, 21, 28, 38, 49, 67, 91, 122, 169, 226, 312, 423, 578, 791, 1075, 1471, 2003, 2732, 3731, 5080, 6941, 9457, 12908, 17609, 24015, 32776, 44699, 60991, 83206, 113499, 154866, 211239, 288211, 393168, 536370, 731761, 998249, 1361895

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) - 2*a(n-3) + a(n-4) + a(n-5) - 2*a(n-6) + a(n-7) + a(n-8) - 2*a(n-9) + 2*a(n-10) - a(n-11) for n>13.

Empirical g.f.: x*(3 - x - 8*x^2 + 5*x^3 + 6*x^4 - 8*x^5 + 2*x^6 + 4*x^7 - 5*x^8 + 3*x^9 - 6*x^11 + 4*x^12) / ((1 - x)*(1 - x - x^2 + x^3 - x^5 + x^6 - x^8 + x^9 - x^10)). - Colin Barker, Oct 30 2018

Example

All solutions for n=4:
..3..3....2..2....3..3
..3..2....2..0....3..2
..2..0....2..0....2..0
..2..0....2..0....3..3

Crossrefs

Column 2 of A241435.

Sequence in context: A306220 A057673 A279398 * A200109 A156060 A272476

Adjacent sequences: A241426 A241427 A241428 * A241430 A241431 A241432

Keyword

nonn

Author

R. H. Hardin, Apr 22 2014

Status

approved