246141

Appears in sequences

• a(n) = a(n-1) + 20*a(n-2), n >= 2; a(0)=1, a(1)=1.at n=8A053428
• Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 10 ones in any 5 X 5 X 5 subtriangle.at n=13A153993