Thanks a ton. I found finite calculus very interesting and useful ! On Fri, Nov 6, 2009 at 11:35 AM, abhijith reddy <abhijith200...@gmail.com>wrote:
> Thank you so much ! :) > > > On Fri, Nov 6, 2009 at 11:00 AM, Prunthaban Kanthakumar < > pruntha...@gmail.com> wrote: > >> On a related note, >> The solution I gave you is to find the nth element in the kth series. >> If you want to sum the first 'n' elements of the kth series (call the >> function s(n,k)), then it is easy to see that, >> >> *s(n,k) = f(n+1, k+1) - 1* >> >> where f(n+1, k+1) is the (n+1)th element in the (k+1)th series. >> This can also be easily done using the summation operator of 'finite >> calculus'. >> >> >> On Fri, Nov 6, 2009 at 10:50 AM, Prunthaban Kanthakumar < >> pruntha...@gmail.com> wrote: >> >>> This is a 'finite calculus' (differences & summations) problem. >>> You can solve it using difference operator (actually its inverse which >>> gives you the discrete integration which is nothing but summation). >>> If you do not know finite calculus, Google for it (or refer Concrete >>> Mathematics by Knuth). >>> >>> The solution for any k is. >>> >>> *f(n) = nC(k+1) + nC(k-1) + nC(k-3) + .... (all the way down to nC0 or >>> nC1 depends on k is odd or even).* >>> >>> Here nCr is the binomial coefficient "n choose r". >>> >>> Eg: Let k = 3, n = 4 >>> >>> f(4) = 4C4 + 4C2 + 4C0 = 1 + 6 + 1 = 8 >>> >>> Another, k = 3 and n = 5 >>> >>> f(5) = 5C4 + 5C2 + 5C0 = 5 + 10 + 1 = 16 >>> >>> >>> On Wed, Nov 4, 2009 at 11:23 AM, abhijith reddy < >>> abhijith200...@gmail.com> wrote: >>> >>>> Is there a way to find the sum of the Kth series ( Given below) >>>> >>>> K=0 S={1,2,3,4,5,6,....} >>>> K=1 S={1,2,4,7,11,16..} common diff = 1,2,3,4 5 ... >>>> K=2 S={1,2,4,8,15,26...} common diff = 1,2,4,7 11... (series with >>>> K=1) >>>> K=3 S={1,2,4,8,16,31...} common diff = 1,2,4,8 15... (series with >>>> K=2) >>>> >>>> Note that the common difference of Kth series is the (K-1) series >>>> >>>> Any ideas ?? >>>> >>>> -- >>>> >>>> You received this message because you are subscribed to the Google >>>> Groups "Algorithm Geeks" group. >>>> To post to this group, send email to algoge...@googlegroups.com. >>>> For more options, visit this group at >>>> http://groups.google.com/group/algogeeks?hl=en. >>>> >>>> >>>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Algorithm Geeks" group. >> To post to this group, send email to algoge...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/algogeeks?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algoge...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > -- nikhil- -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algoge...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.