Sunday

August 30, 2015
Posted by **dayo** on Tuesday, November 9, 2010 at 8:24am.

- Math -
**Writeacher**, Tuesday, November 9, 2010 at 8:39amThink "squares."

http://www.mathsisfun.com/square-root.html

- Maths -
**Dr Russ**, Tuesday, November 9, 2010 at 8:48amThe subject is maths.

These are positive integers n such that the sum of the divisors of n, excluding 1, is a multiple of the number of divisors of n.

so the next numbers in the sequence are

64, 81, 100, 121, 289,

As examples

The 9 divisors of 36 are {1,2,3,4,6,9,12,18,36}, giving sum (1+2+3=4+6+9+12+18+36)-1=90 which is a multiple of 9. Thus 36 is a term of the sequence.

The 3 divisors of 25 are

{1,5,25} giving a sum (1+5+25)-1=30 which is a multiple of 3. Thus 25 is a term of the sequence.

- college -
**dayo**, Tuesday, November 9, 2010 at 8:51amit's not square cuz i want the relation btw these numbers 1,2,4,9,16,25,36,.. NOT btw these numbers 1,4,9,16,25,...

- maths -
**Dr Russ**, Tuesday, November 9, 2010 at 10:02amAgreed it is not squares. It is the sequence as I described above.