a(n) = F(3)*F(n)*F(n+1) + F(4)*F(n+1)^2 - F(4) if n even, F(3)*F(n)*F(n+1) + F(4)*F(n+1)^2 if n odd, where F(n) is the n-th Fibonacci number (A000045).
A080143
a(n) = F(3)*F(n)*F(n+1) + F(4)*F(n+1)^2 - F(4) if n even, F(3)*F(n)*F(n+1) + F(4)*F(n+1)^2 if n odd, where F(n) is the n-th Fibonacci number (A000045).
Terms
- a(0) =0a(1) =5a(2) =13a(3) =39a(4) =102a(5) =272a(6) =712a(7) =1869a(8) =4893a(9) =12815a(10) =33550a(11) =87840a(12) =229968a(13) =602069a(14) =1576237a(15) =4126647a(16) =10803702a(17) =28284464a(18) =74049688a(19) =193864605a(20) =507544125a(21) =1328767775a(22) =3478759198a(23) =9107509824a(24) =23843770272a(25) =62423800997a(26) =163427632717
External references
- oeis: A080143