Break the sequence into pairs : (246,20),(689,66),(479,55) ,(369,?)
Add up the numbers in each pair. We get 266,755 and 534 .Note the last 2 digits ,i.e
66, 55 and 34. The sum of each pair modulo 100(last 2 digits) gives second term in next pair .
Hence as the next number to be found is a second term ,it must be 34.