a(n) = (F(3*n) - 2*F(n))/6, where F=A000045 (the Fibonacci sequence).
A049674
a(n) = (F(3*n) - 2*F(n))/6, where F=A000045 (the Fibonacci sequence).
Terms
- a(0) =0a(1) =0a(2) =1a(3) =5a(4) =23a(5) =100a(6) =428a(7) =1820a(8) =7721a(9) =32725a(10) =138655a(11) =587400a(12) =2488344a(13) =10540920a(14) =44652257a(15) =189150325a(16) =801254167a(17) =3394167980a(18) =14377927684a(19) =60905881300a(20) =258001457065
External references
- oeis: A049674