S
what is the next letter e h l q
c
Q
59 is the next number in this series.
The series goes like this........ 15, 12+52=26, 22+62=40, 42+02=16, 12+62=37, 32+72=58, 52+82=89,...........I guess now u know the next term which is....82+92=145 So its the series of sum of squares of the digits of previous term.
y
what is the next letter e h l q
X
c
Q
The next (and last) letter is C. Just as a countdown counts backwards, this series is "countdown" spelled backwards.
20? Just a guess
c is next
y
S
T
It's the letter D of course! Haven't you heard of Jason D?!