a(n) = 11^n - n^12.

Terms

a(0) =1a(1) =10a(2) =-3975a(3) =-530110a(4) =-16762575a(5) =-243979574a(6) =-2175010775a(7) =-13821800030a(8) =-68505117855a(9) =-280071588790a(10) =-974062575399