a(n) = Sum_{j=0..floor(n/2)} T(2*j + q), where T(n) are generalized tribonacci numbers (A001644) and q = n - 2*floor(n/2).

A074475

a(n) = Sum_{j=0..floor(n/2)} T(2*j + q), where T(n) are generalized tribonacci numbers (A001644) and q = n - 2*floor(n/2).

Terms

    a(0) =3a(1) =1a(2) =6a(3) =8a(4) =17a(5) =29a(6) =56a(7) =100a(8) =187a(9) =341a(10) =630a(11) =1156a(12) =2129a(13) =3913a(14) =7200a(15) =13240a(16) =24355a(17) =44793a(18) =82390a(19) =151536a(20) =278721a(21) =512645a(22) =942904a(23) =1734268a(24) =3189819a(25) =5866989a(26) =10791078a(27) =19847884a(28) =36505953a(29) =67144913

External references