Third binomial transform of A010685 (period 2: repeat 1,4).

Terms

a(0) =1a(1) =7a(2) =34a(3) =148a(4) =616a(5) =2512a(6) =10144a(7) =40768a(8) =163456a(9) =654592a(10) =2619904a(11) =10482688a(12) =41936896a(13) =167759872a(14) =671064064a(15) =2684305408a(16) =10737319936a(17) =42949476352a(18) =171798298624a(19) =687193980928