Respuesta :

Catya
the pattern i see is:
double 6's
+2 = 8,
double 8's
+3 = 11,
double 11's
+4 = 15,
double 15's
+5 = 20,
double 20's
+6 = 26,
double 26's
+7 = 33
double 33's

66, 88, 1111, 1515, 2020, 2626, 3333, ....