Hello this is the solution of non hemogenous recursion ,are you agree with my solution:

[{a[n+2]-2a[n+1]+a[n]Šn,a[0]Š1,a[1]Š2},a,n]

(r-1)^2 = 0 => r= 1

an(h) =c1 + nc2

an(p)=a0+a1n

an=c1+nc2+n^2

c1=1

c2=0 then an= 1+n^2

Thank you very much for your attention