a(n) = n^11 - 1.

Terms

a(0) =0a(1) =2047a(2) =177146a(3) =4194303a(4) =48828124a(5) =362797055a(6) =1977326742a(7) =8589934591a(8) =31381059608a(9) =99999999999a(10) =285311670610a(11) =743008370687