Need formula for:
f(x) => y
where x and y are:
0..4 => 1
5..14 => 2
15..29 => 3
30..49 => 4
etc.
i also need the opposite:
f(a) => b,c
where a,b and c are:
1 => 0,5
2 => 5,10
3 => 15,15
4 => 30,20
I'm stumped. Thanks in advance! I'm currently pursuing getting the largest consecutive numbers which satisfy n * (n+1) / 2 by getting a sqrt on the sum (after dividing by 5) since the sums are scaled x5.