30230

Appears in sequences

• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,0,2.at n=4A037659
• Sequence A014486 shown in base 4.at n=38A085185
• Place n points on each of the three sides of a triangle, 3n points in all; a(n) = number of nondegenerate triangles that can be constructed using these points (plus the 3 original vertices) as vertices.at n=18A130748
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (0, 1, 0), (1, -1, 1), (1, 1, -1)}.at n=10A148365
• Coefficient of x in the reduction by x^2->x+1 of the polynomial p(n,x) defined below in Comments.at n=18A192762
• G.f.: AGM( (1-x)/(1+x), (1+3*x)/(1-3*x) ).at n=10A248169