a(n) + a(n+1) + a(n+2) = 2^n.

Terms

a(0) =0a(1) =0a(2) =2a(3) =2a(4) =4a(5) =10a(6) =18a(7) =36a(8) =74a(9) =146a(10) =292a(11) =586a(12) =1170a(13) =2340a(14) =4682a(15) =9362a(16) =18724a(17) =37450a(18) =74898a(19) =149796a(20) =299594a(21) =599186a(22) =1198372a(23) =2396746a(24) =4793490a(25) =9586980a(26) =19173962a(27) =38347922a(28) =76695844a(29) =153391690