What is the next number of the following sequence 7, 14, 55, 110, ....?

Concept:

Some number series are not built from simple addition/multiplication patterns but from a ‘reverse-and-add’ rule: each next term equals the current term plus the number formed by reversing that term's own digits (next term = term + reverse(term)).

Application:

1. 7 reversed is 7 (a single digit is its own reverse); 7 + 7 = 14.

2. 14 reversed is 41; 14 + 41 = 55.

3. 55 reversed is 55 (it is a palindrome); 55 + 55 = 110.

4. 110 reversed is 011, i.e. 11 (the leading zero is dropped); 110 + 11 = 121.

Cross-check:

This reverse-and-add relationship is applied consistently across all four given transitions (7→14, 14→55, 55→110), not just fitted to the last step, confirming that the same relationship extends to give 121 as the next term.

So the next number in the sequence is 121.