October 12, 2009

15, 161, 1771, 19481, 214291,______?



Next number in the sequence
15, 161, 1771, 19481, 214291 is

Options:

1) 1942651
2) 135611101
3) 2424561
4) 1357101
5) 345372101
6) 1357201
7) 23651121
8) 1764924
9) 125461
10) 234255

10 comments:

  1. Ignore my prev posts...
    its (6) 1357201

    ReplyDelete
  2. I believe the answer is intended to be 2357201?

    But it seems to me that the first term of the sequence does not fit and should perhaps be omitted?

    Starting with 161 I agree, but starting with 15 I get:

    15,165,1815,19965,219615,2415765

    Or am I missing something very subtle?

    ReplyDelete
  3. The answer is 2357201.

    I agree with beetrootchesself that the first term just does not make sense.

    ReplyDelete
  4. It's 1357201 since there is no carry over.

    Numbers are generated by adding together neighbouring digits of the preceding term and bracketting them between 1's. Start from the right and carry over tens to the next sum.

    Carry overs from sum at right in bold.
    15
    161 : 1 (1+5) 1
    1771 : 1 (1+6) (6+1) 1
    19481 : 1 (1+7+1) (7+7) (7+1) 1
    214291 : 1+1 (1+9+1) (9+4+1) (4+8) (8+1) 1
    The first term is "2" because of the carry over from (1+9+1)
    1357201 : 1 (2+1) (1+4) (4+2+1) (2+9+1) (9+1)1
    The first term returns to "1" because there is no carry over from (2+1)

    ReplyDelete
  5. how the hell you all get 2357201?
    the answer is 1357201...

    ReplyDelete
  6. yeah, the answer is 1357201. nice explanation.

    starting from 2 nd number, they multiplied with 11. tht's y they got 2357201. But its not correct. first number will be missed in sequence.

    ReplyDelete