it seems to have a different increasing for evens and odds....but, if my numbers are right, i think the evens have a sequence of increasing for an arithmetic progression of second order and the odds have another, but starting in another number....
the increasing i calculated was (read [n] = floor(n)): odd: 2(1+2+...[n/2]-1)+[n/2] even: 2(1+2+...n) both can be easily calculated but i can't find a closed formula witch can be used for both... i wish i did all right here.. :P 2009/10/19 2shar007 <[email protected]> > > In the puzzle, /_\ > /_\/_\ > /_\/_\/_\ this is having 10 > vertices, we are to find the no.of triangles which is 13 here > > I tried to derive a general formula, but couldn't :( > What I understood was triangles have vertices as n(n+1)/2, > n=2,3,4,5.................. > > Also that the no. of triangles for k(k+1)/2 vertices is no.of > triangles in k(k-1)/2 + triangles of all sizes with atleast one > vertex in the larger triangle. > > will be grateful if someone could give a fitting reply > Thanks in advance > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "google-codejam" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-code?hl=en -~----------~----~----~----~------~----~------~--~---
