a(1) = a(2) = 0; a(3) = 2; for n >= 4, a(n) = (prime(n-1)-2)*a(n-1), where prime(n) is the n-th prime.
A121406
a(1) = a(2) = 0; a(3) = 2; for n >= 4, a(n) = (prime(n-1)-2)*a(n-1), where prime(n) is the n-th prime.
Terms
- a(0) =0a(1) =0a(2) =2a(3) =6a(4) =30a(5) =270a(6) =2970a(7) =44550a(8) =757350a(9) =15904350a(10) =429417450a(11) =12453106050a(12) =435858711750
External references
- oeis: A121406