If N be the numbers of natural numbers less than 2009 which can be expressed in the form of [x[x]] for some positive real x then sum of the digits of N.([.] denotes greatest integer function).
If N be the numbers of natural numbers less than 2009 which can be expressed in the form of [x[x]] for some positive real x then sum of the digits of N.([.] denotes greatest integer function).