The numbers seven, eleven, fifteen, nineteen make a sequence where the numbers go up by 4 each time. But if you count the number of letters in each word, you get a sequence of numbers that goes up by 1 each time – 5, 6, 7, 8.
The list above has 4 numbers in it.
Find a list with 6 numbers in it.
(That is, you need 6 numbers that go up by the same amount each time, but the number of letters is an arithmetic sequence too.)