Answer-250, 279, 311, 349, 396, ?

First, calculate the differences 27925029 31127932 34931138 39634947 The differences are 29,32,38,47. Now, lets look at the differences between these differences 32293 38326 47389 The second-order differences are 3,6,9, which are increasing by 3. If this pattern continues, the next difference should be 9312 Now, add this to the last difference 471259 Finally, add this to the last term in the series 39659 455