null sequence

13 LETTERS · STARTS WITH N

null sequence is a valid 13-letter word worth 23 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

N1U1L1L1S1E1Q10U1E1N1C3E1

1 + 1 + 1 + 1 + 0 + 1 + 1 + 10 + 1 + 1 + 1 + 3 + 1 =23 PTS

DOUBLE WORD → 46TRIPLE WORD → 69

MEANING

What does null sequence mean?