Question

Find out the wrong number in the series 1, 3, 10, 21, 64, 129, 356, 777

Answer 1

3 = 1× 2 + 1

10 = 3× 3 + 1

21 = 10× 2 + 1

64 = 21 × 3 +1

129 = 64 × 2 + 1

356 = 129 × 2 +98

SO 356