Number of points of l_1 norm n in the "diamond" lattice D^+_4.

Terms

a(0) =1a(1) =0a(2) =40a(3) =32a(4) =272a(5) =160a(6) =888a(7) =448a(8) =2080a(9) =960a(10) =4040a(11) =1760a(12) =6960a(13) =2912a(14) =11032a(15) =4480a(16) =16448a(17) =6528a(18) =23400a(19) =9120a(20) =32080a(21) =12320a(22) =42680a(23) =16192a(24) =55392a(25) =20800a(26) =70408a(27) =26208a(28) =87920a(29) =32480