calculation using powers ?

[oldandrew]

Hi any Tips, i am not looking for the full code as i am trying to learn it myself.

the sum is 3 to power of 3, minus 5 to power of 5, plus 7 to pow of 7, minus 9 to pow 9, ect ect its reoccuring going up in powers adding one sum then minus the next ect till I reach the number I want.

would I have 2 separate lines i.e

i = 3 raised to the power 3 , then 7 rasied to power of 7 ect
to give me the plus

then would i have

j = 5 to pow 5 ect to give me minus

or am I going down the wrong track

thanks if you can advise

as I would like to solve it before I get my pension

[CornedBee]

Not quite sure what you want. Is this it?

int i=0, j=3, sum=0;
while(sum < numberYouWantToReach) {
  sum += (i%2)?(-(Math.pow(j,j))):(Math.pow(j,j));
  i++; j += 2;
}