Apply partial sum operator twice to Fibonacci numbers.

Terms

a(0) =0a(1) =1a(2) =3a(3) =7a(4) =14a(5) =26a(6) =46a(7) =79a(8) =133a(9) =221a(10) =364a(11) =596a(12) =972a(13) =1581a(14) =2567a(15) =4163a(16) =6746a(17) =10926a(18) =17690a(19) =28635a(20) =46345a(21) =75001a(22) =121368a(23) =196392a(24) =317784a(25) =514201a(26) =832011a(27) =1346239a(28) =2178278a(29) =3524546