a(n) = T(n,n-4), T given by A026536. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 4.

A026541

a(n) = T(n,n-4), T given by A026536. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 4.

Terms

    a(0) =1a(1) =2a(2) =9a(3) =19a(4) =65a(5) =136a(6) =430a(7) =886a(8) =2721a(9) =5538a(10) =16793a(11) =33887a(12) =102102a(13) =204856a(14) =615024a(15) =1229280a(16) =3682545a(17) =7341786a(18) =21963161a(19) =43712603a(20) =130648089a(21) =259726104a(22) =775797750a(23) =1541084142a(24) =4601346295a(25) =9135694750a(26) =27270124455a(27) =54125522793

External references