a(n) = Sum_{d|n} (-1)^(d-1)*d^11.

Terms

a(0) =1a(1) =-2047a(2) =177148a(3) =-4196351a(4) =48828126a(5) =-362621956a(6) =1977326744a(7) =-8594130943a(8) =31381236757a(9) =-99951173922a(10) =285311670612a(11) =-743375186948