1,2

Column 1 of A196544

R. H. Hardin, Table of n, a(n) for n = 1..200

Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4).

Empirical: G.f. x*(x-1)*(x^2+3*x+1) / ( -1+x+x^2+3*x^3+x^4 ). - R. J. Mathar, Jul 25 2012

All solutions for n=4

..0....0....1....0....0....1....0

..2....1....0....2....2....1....2

..2....2....2....1....1....2....0

..0....0....0....1....0....0....1

Sequence in context: A104528 A177115 A316087 * A173099 A111928 A248054

Adjacent sequences: A196534 A196535 A196536 * A196538 A196539 A196540

nonn

R. H. Hardin Oct 03 2011

approved