a(n) = T(n, n-4), T given by A026519. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 4.

A026524

a(n) = T(n, n-4), T given by A026519. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 4.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =28a(4) =65a(5) =201a(6) =430a(7) =1316a(8) =2721a(9) =8259a(10) =16793a(11) =50680a(12) =102102a(13) =306958a(14) =615024a(15) =1844304a(16) =3682545a(17) =11024331a(18) =21963161a(19) =65675764a(20) =130648089a(21) =390374193a(22) =775797750a(23) =2316881892a(24) =4601346295a(25) =13737041045a(26) =27270124455

External references