a(n) = (F(6*n+5) - 1)/4, where F = A000045 (the Fibonacci sequence).

A049663

a(n) = (F(6*n+5) - 1)/4, where F = A000045 (the Fibonacci sequence).

Terms

    a(0) =1a(1) =22a(2) =399a(3) =7164a(4) =128557a(5) =2306866a(6) =41395035a(7) =742803768a(8) =13329072793a(9) =239180506510

External references