a - 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, ...
a(n) =1(n - 1) .......This is called "rising factorial"
b - 1, 3, 12, 60, 360, 2520, 20160, 20160, 181440, 1814400, 19958400, 239500800, 3113510400, ...
a(n) =1(n + 1) / 2 ............This is called "rising factorial"
b(32) / a(32) =[1(32+1)! / 2] / 1[32 - 1]! =[33!/2] / 31! = 528