Find a sequence of six 5-digit prime numbers a,b,c,d,e,  such that :

b = a + 2, c = b + 4, d = c + 6, e = d + 8, f = e + 10.  

Example:   21557,21559,21563,21569,21577,21587.

This is a span of 30 integers, of which only six are allowed to be prime.

There are four other sequences to find.