Hi all,

My sister recently gave me the following puzzle and insited that it was definetly possible. After looking briefly at it, I cannot find any suitable solutions. Can anyone help ?

Take the sequence

-2,2,4,6,6

this sequence is used to work out a subsequent sequence

this is done as follows

the first term (-2) is added to the second term (2) to form 0

then the 1st term is added to the 3rd

the 1st to the fourth

the 1st to the fifth

so far we have 0,2,4,4

then you do second term added to third

second added to fourth

second added to fifth

its now 0,2,4,4,6,8,8

then you do third added to fourth

third added to fifth

then fourth added to fifth

so the final sequence is 0,2,4,4,6,8,8,10,10,12

-------------------------------------

the puzzle is this

starting with the final sequence, what was the original one (the one with the terms)

the final squence given is as follows

0,2,4,4,6,8,9,11,13,15

Any help would be much appreciated

Thanks

Nicky