A073889 a(1) = 1, a(2) = 3; for n>2, a(n) = {a(n-1)*a(n+1)}^(1/n) or a(n+1) = a(n)^n/a(n-1).

1, 3, 9, 243, 387420489, 35917545547686059365808220080151141317043