A115043 a(0)=3, a(1)=5. a(n) = a(n-1)*a(n-2) if n odd, else a(n) = a(n-1)/a(n-2).

3, 5, 15, 3, 45, 15, 675, 45, 30375, 675, 20503125, 30375, 622782421875, 20503125, 12768985843505859375, 622782421875, 7952299928506168842315673828125, 12768985843505859375

Offset: 0

Author

Giovanni Teofilatto, Feb 28 2006

Keywords

• easy
• nonn

Comments

All divisors >1 of the terms are also in the sequence.

Crossrefs

Cf. A115033, A115034, A174348.

Formula

a(n) = a(n-2)*a(n-4) if n odd. a(n)=a(n-3) if n even.

a(2n+1) = 3^Fibonacci(n+1) * 5^Fibonacci(n).

a(2n) = 3^Fibonacci(n-1) * 5^Fibonacci(n-2).

Extensions

Formulas corrected by R. J. Mathar, Mar 16 2010