a(n) = T(n,n-3), T given by A026568. Also a(n) = number of integer strings s(0),...,s(n) counted by T, such that s(n)=3.

A026572

a(n) = T(n,n-3), T given by A026568. Also a(n) = number of integer strings s(0),...,s(n) counted by T, such that s(n)=3.

Terms

    a(0) =1a(1) =2a(2) =8a(3) =19a(4) =56a(5) =140a(6) =376a(7) =953a(8) =2474a(9) =6286a(10) =16097a(11) =40880a(12) =104069a(13) =264052a(14) =670414a(15) =1699831a(16) =4310546a(17) =10924970a(18) =27690075a(19) =70168812a(20) =177820791a(21) =450618964a(22) =1142004584a(23) =2894347667a(24) =7336297080a(25) =18597140982a(26) =47148420564

External references