a(n) = -n^3 + 7*n^2 - 5*n + 1.

Terms

a(0) =1a(1) =2a(2) =11a(3) =22a(4) =29a(5) =26a(6) =7a(7) =-34a(8) =-103a(9) =-206a(10) =-349a(11) =-538a(12) =-779a(13) =-1078a(14) =-1441a(15) =-1874a(16) =-2383a(17) =-2974a(18) =-3653a(19) =-4426a(20) =-5299a(21) =-6278a(22) =-7369a(23) =-8578a(24) =-9911a(25) =-11374a(26) =-12973a(27) =-14714a(28) =-16603a(29) =-18646