A239594 Number of n X 2 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 one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.
4, 3, 4, 4, 5, 7, 8, 11, 12, 16, 19, 24, 30, 36, 46, 55, 70, 85, 106, 131, 161, 201, 246, 307, 377, 468, 578, 714, 885, 1091, 1353, 1669, 2067, 2554, 3158, 3907, 4827, 5974, 7381, 9132, 11288, 13959, 17262, 21340, 26394, 32628, 40353, 49890, 61693, 76284, 94321
Offset: 1
Keywords
Examples
All solutions for n=4: ..2..0....2..0....3..0....2..0 ..2..0....2..0....2..3....2..0 ..3..0....2..0....3..2....3..0 ..2..3....2..0....2..3....3..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Column 2 of A239599.
Formula
Empirical: a(n) = a(n-2) + a(n-5) for n>6.
Empirical g.f.: x*(4 + 3*x + x^3 + x^4 - x^5) / (1 - x^2 - x^5). - Colin Barker, Oct 26 2018
Comments