### What is the missing number in this series

1,16,36,__,81,100,144

See Solution
Series is the square of non prime numbers, 1

^{2}, 4^{2}, 6^{2}, 8^{2}, 9^{2}, 10^{2}, 12^{2}. these are square in sequence excluding the prime numbers 2,3,5,7 and 11. Thus the missing number in series should be 8^{2}=64.
fivebee says

64

fivebee says

guess i dont mind half a year ago? (49)

puzzlersworld says

What you thought 6 months ago was correct :), This series is square of non prime numbers, See Solution above(link to expand solution), correct answer is 64.