a(n) = 2^r*3^s where r = n(n+1)/2 and s = n(n-1)/2.

A081955

a(n) = 2^r*3^s where r = n(n+1)/2 and s = n(n-1)/2.

Terms

    a(0) =1a(1) =2a(2) =24a(3) =1728a(4) =746496a(5) =1934917632

External references