linkage formula

15 LETTERS · STARTS WITH L

linkage formula is a valid 15-letter word worth 24 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

L1I1N1K5A1G2E1F4O1R1M3U1L1A1

1 + 1 + 1 + 5 + 1 + 2 + 1 + 0 + 4 + 1 + 1 + 3 + 1 + 1 + 1 =24 PTS

DOUBLE WORD → 48TRIPLE WORD → 72

MEANING

What does linkage formula mean?