a(n) = Product_{1 <= i < j <= n} (c(i) + c(j)); c = A002808 = composite numbers.
A203530
a(n) = Product_{1 <= i < j <= n} (c(i) + c(j)); c = A002808 = composite numbers.
Terms
- a(0) =1a(1) =10a(2) =1680a(3) =5569200a(4) =426645273600
External references
- oeis: A203530