tetra(3) * tetra(6) = (3*4*5/6)*(6*7*8/6) = (3*4*5/6)*(7*8) = (60/6)*56 = 10*56 = 560 = tetra(14)
the smallest [tetrahedral number] that is the product of two tetrahedral numbers both greater than one
"tetra(3) * tetra(6) = (3*4*5/6)*(6*7*8/6) = (3*4*5/6)*(7*8) = (60/6)*56 = 10*56 = 560 = tetra(14)" What is the definition of "560"?