Design simple key calculating algorithm

In attachment you have 2 series of data: SEED (S1-S4) and KEY (K1-K4). Both SEED and KEY are 32-bit long, but actually they consist of two 16-bit numbers, so we can consider it as 16-bit. The task is to determine a formula or algorithm, which converts SEED into KEY (hash-table of all combinations is not an option). If you see at the binary representation (...BIN columns in attachment) - obviously there exists a relation between SEED and KEY. Some bit shifting, swapping, negating, multiplication should be enough to calculate the KEY.