a(n) = T(n,n-2), T given by A026536. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 2.

A026539

a(n) = T(n,n-2), T given by A026536. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 2.

Terms

    a(0) =1a(1) =1a(2) =5a(3) =8a(4) =27a(5) =49a(6) =150a(7) =284a(8) =845a(9) =1625a(10) =4797a(11) =9288a(12) =27377a(13) =53207a(14) =156900a(15) =305720a(16) =902394a(17) =1761882a(18) =5205950a(19) =10181720a(20) =30114073a(21) =58983859a(22) =174609162a(23) =342449340a(24) =1014555607a(25) =1992082339a(26) =5906040623a(27) =11608506392a(28) =34438443075

External references