Henry Bauer

=si((11-residuo(suma((residuo(b2;10)*2)+(residuo(entero(b2/10);10)*3)+(residuo(entero(b2/100);10)*4)+(residuo(entero(b2/1000);10)*5)+(residuo(entero(b2/10000);10)*6)+(residuo(entero(b2/100000);10)*7)+(residuo(entero(b2/1000000);10)*2)+(residuo(entero(b...