Number of subsets of {1..n} that contain exactly three odd numbers.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =4a(5) =8a(6) =32a(7) =64a(8) =160a(9) =320a(10) =640a(11) =1280a(12) =2240a(13) =4480a(14) =7168a(15) =14336a(16) =21504a(17) =43008a(18) =61440a(19) =122880a(20) =168960a(21) =337920a(22) =450560a(23) =901120a(24) =1171456a(25) =2342912a(26) =2981888a(27) =5963776a(28) =7454720a(29) =14909440