Nothing found here: http://www.research.att.com/~njas/s...19,42&sort=0&fmt=0&language=english&go=Search Without commas this returns 432 pages of results; looked through the first few but there was nothing obvious. So we need more terms to deduce the sequence. Of course, any number can be the answer, for example 99, because these are the roots of the equation x^7-182*x^6+10500*x^5-252586*x^4+2762303*x^3-13306896*x^2+24059196*x-13272336

Even I searched there, in vain Yeah, but then how do we express the general term, say 'n'th term of the series ?? :undecided As you already said, we probably need some more terms ... :thinking:

Assuming that is enough to deduce the series, then using the same technique as before I get 113. Code: 1 2 1 7 5 4 12 5 0 -4 19 7 2 2 6 42 23 16 14 12 6 113 71 48 32 18 6

Hi all, sorry for my late reply. Consider alternative terms set 2 ie 2,12,42 12-2 = 10 = (2)^3 + 2 42-12 = 30 = (3)^3 + 3 Consider alternative terms set 1 ie. 1,7,19 7-1 = 6 = (2)^2 + 2 19-7= 12 = (3)^2 + 3 as the next number belongs to alternative set 1 ( because next numbers postion is odd) next number should be 19 + (4)^2 + 4 = 39 So the answer is 39.

I too thought in the same angle. But some thing went wrong 1, 2, 7, 12, 19, 42 The diff b/w 1st and third is 6 (7-1) The diff b/w 5th and 3rd is 12 (19-7) So,The diff b/w 7th and 5th should be 18 (37-19) which follows multiples of 6. Similarly, the diff b/w 4th and 2nd is 10 (12-2) the diff b/w 6th and 4th is 30 (42-12)

Your logic would be correct if the 6th number is 32 instead of 42 so that the diff b/w 6th and 4th is 20 (32-12) i.e then 2nd difference series will be 10,20,30 like first difference series 6,12,18.