Max Alekseyev wrote: > Does anybody understand the definition of A002848 and how it produces > the listed terms? No, I don't. If we take e.g. n=5 then from the definition Number of solutions of x+y=z from {1,2,...,n} I would count these as solutions: 1+2=3 1+3=4 1+4=5 2+3=5 This would give me a(5)=4. The listed term is a(5)=2. Cheerious, Rainer