Series

The answer is 6176
  EXPLANATION:
     The first and the last number of the series is same and it starts from 1 and incremented by 1.
i.e  1a1,2b2,3c3,............etc
     The middle number of 1st number(121)=2
     The middle number of 2nd  number(232)=3(1+2)[adding 1st no and middle no of 121]
     The middle number of 3rd number(353)=5(2+3)[from232]
     The middle number of 4th number(484)=8(3+5)[from353]
     The middle number of 5th number(5125)=12(4+8)[from484]
    hence the middle number of 6th number be 17(5+12)[from 5125]
    so the next number in the series is 6176