a(n) is the forgotten index of the Fibonacci cube Gamma(n).

Terms

a(0) =2a(1) =10a(2) =52a(3) =158a(4) =466a(5) =1192a(6) =2914a(7) =6722a(8) =14972a(9) =32286a(10) =67914a(11) =139824a(12) =282754a(13) =562970a(14) =1105892a(15) =2146846a(16) =4124258a(17) =7849496a(18) =14815202a(19) =27752338a(20) =51632620a(21) =95465502a(22) =175508250a(23) =320981472a(24) =584214530a(25) =1058602666a(26) =1910305300a(27) =3434059166a(28) =6151218034a(29) =10981579528