"DHK" (bracelet, identity, unlabeled) transform of 1,3,5,7,...

Terms

a(0) =1a(1) =1a(2) =3a(3) =8a(4) =15a(5) =34a(6) =70a(7) =162a(8) =388a(9) =1020a(10) =2729a(11) =7580a(12) =21112a(13) =59398a(14) =166990a(15) =471635a(16) =1332492a(17) =3776712a(18) =10721570a(19) =30518960a(20) =87046334a(21) =248852142a(22) =712831894a(23) =2045974474a(24) =5882821341a(25) =16943916873a(26) =48878646537a(27) =141209193981