hello shenoy,
see 1st two members of series .. SAJ, KTB...
1st letter of 2nd member is d successor of 3rd letter of 1st member, i.e.,, K&J.
similarly, 2nd letter is always d sucessor of 1st letter of the previous member.. and 3rd letter is of middle letter.. i.e., T of S and B of A.
got it?