A175138 a(n) = Product_{i=1..n-1} a(i), with a(1) = 3 and a(2) = 5.

3, 5, 15, 225, 50625, 2562890625, 6568408355712890625, 43143988327398919500410556793212890625, 1861403728794734215467410604755702820123364205073812627233564853668212890625

Offset: 1

Author

Giovanni Teofilatto, Feb 23 2010

Keywords

• nonn
• easy
• changed

Comments

Except for first three terms, a(n) = (a(n-1))^2.

Programs

Mathematica

Join[{3,5},NestList[#^2&,15,7]] (* Harvey P. Dale, Feb 08 2013 *)

Formula

a(n) = 15^(2^(n-3)), n > 2.

Extensions

Edited by Jaroslav Krizek and R. J. Mathar, Mar 04 2010