Replace number with repeated characters

join(",", array_unique(split(",", $values)))

([a-z0-9]{2})\1\1

>>> import re
>>> re.sub(r'([a-z0-9]{2})\1\1', r'', "abababwhatevercdcdcd")
'whatever'
>>> re.sub(r'([a-z0-9]{2})\1\1', r'', "wabababhatevercdcdcd")
'whatever'

string.replaceAll("((.)\\2{2})\\2+","$1");

void x(char *s, int n)
{
    char *cp= s;
    int i, j;

    while (*cp) {
        i= 1;
        while (*(cp+i) && ((*(cp+i))&~32)==((*cp)&~32)) i++;    // count character repeat
        for (j=0; j<n && j<i; j++)              // repeat at most max repeat (n)
            *s++ = *(cp+j);
        cp += i;
    }
    *s= '\0';
}

const randomChars = 'ABaaBCDdeGFAAR';

let h= {};
randomChars.toUpperCase().split('').forEach(c => h[c]=++h[c]||1);
let r = Object.keys(h).sort().map(k => h[k]+k).join(' ');

console.log(r);