a(n) = T(n, n-3), T given by A026519. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 3.

A026523

a(n) = T(n, n-3), T given by A026519. 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) =16a(4) =52a(5) =104a(6) =319a(7) =635a(8) =1910a(9) =3786a(10) =11304a(11) =22344a(12) =66514a(13) =131264a(14) =390266a(15) =769578a(16) =2286996a(17) =4508580a(18) =13397075a(19) =26412001a(20) =78489235a(21) =154773696a(22) =460030947a(23) =907432695a(24) =2697786052a(25) =5323519838a(26) =15830906756a(27) =31251588060

External references