Sum of successive Fibonacci numbers F(n) : a(n) = Sum_{k = 0..n} F(n+k).

Terms

a(0) =0a(1) =2a(2) =6a(3) =18a(4) =50a(5) =136a(6) =364a(7) =966a(8) =2550a(9) =6710a(10) =17622a(11) =46224a(12) =121160a(13) =317434a(14) =831430a(15) =2177322a(16) =5701290a(17) =14927768a(18) =39083988a(19) =102327390a(20) =267903350a(21) =701391022a(22) =1836283246a(23) =4807480608a(24) =12586194000a(25) =32951158706a(26) =86267374854a(27) =225851115906a(28) =591286215650