

A135937


a(1)=1; for n>=2, a(n) = product{da(n1)} (d+1), where the product is over all positive divisors d of a(n1).


1




OFFSET

1,2


COMMENTS

The next term is a lot bigger than 70000! and is too large to include.  Stefan Steinerberger, Dec 31 2007


LINKS

Table of n, a(n) for n=1..5.


EXAMPLE

The positive divisors of a(3)=6 are 1,2,3,6. So a(4) = (1+1)*(2+1)*(3+1)*(6+1) = 2*3*4*7 = 168.


MATHEMATICA

a = {1}; Do[AppendTo[a, Times @@ (Divisors[a[[ 1]]] + 1)], {4}]; a (* Stefan Steinerberger, Dec 31 2007 *)


CROSSREFS

Cf. A135938.
Sequence in context: A281819 A199482 A168649 * A182523 A137532 A072116
Adjacent sequences: A135934 A135935 A135936 * A135938 A135939 A135940


KEYWORD

nonn


AUTHOR

Leroy Quet, Dec 07 2007


EXTENSIONS

a(5) from Stefan Steinerberger, Dec 31 2007


STATUS

approved



