a(n) = 6 + 33*n + 6*binomial(n, 2) - 28*binomial(n, 3) + 20*binomial(n, 4) - 47*binomial(n, 5).

Terms

a(0) =6a(1) =39a(2) =78a(3) =95a(4) =82a(5) =4a(6) =-248a(7) =-904a(8) =-2362a(9) =-5235a(10) =-10398a(11) =-19035a(12) =-32686a(13) =-53294a(14) =-83252a(15) =-125450a(16) =-183322a(17) =-260893a(18) =-362826a(19) =-494469a(20) =-661902a(21) =-871984a(22) =-1132400a(23) =-1451708a(24) =-1839386a(25) =-2305879a(26) =-2862646a(27) =-3522207a(28) =-4298190a(29) =-5205378