A, B, C and D are triangular numbers.
A, B and C are always consecutive while D is their sum.
Determine (and explain as best as possible1) how such sets of values are distributed across the number system.
1. This can be explained in terms of a single variable expression.
(In reply to re(2): an observation
I edited my prior comment to say "only when x is an integer..".
I agree that to find the integers in such a list would be extremely tedious.
Posted by brianjn
on 2009-11-30 19:20:52