Sounds a bit like "normal distribution", or "the bell curve." You can generate numbers that act like that using the "Box–Muller transform." Look up these things.
My attempt at implementing it in GScript:
PHP Code:
function normal() {
temp.e = 2.7182818284590452353602874713526624977572470936999;
return cos(2*pi*random(0, 1)) * (-2 * log(temp.e, random(0, 1)))^0.5;
}
It generates numbers that are more likely to be close to 0.
If you know in advance that you only need numbers 1 through 10 it's probably easier to do it another way.