a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2,3; |s(i) - s(i-1)| <= 1 for i >= 4, s(n) = 1. Also a(n) = T(n,n-1), where T is the array defined in A026082.
A026084
a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2,3; |s(i) - s(i-1)| <= 1 for i >= 4, s(n) = 1. Also a(n) = T(n,n-1), where T is the array defined in A026082.
Terms
- a(0) =3a(1) =13a(2) =33a(3) =98a(4) =278a(5) =804a(6) =2320a(7) =6723a(8) =19515a(9) =56769a(10) =165421a(11) =482793a(12) =1411049a(13) =4129323a(14) =12098151a(15) =35482857a(16) =104169033a(17) =306087111a(18) =900134883a(19) =2649106752a(20) =7801834068a(21) =22992061134a(22) =67799076002a(23) =200040038589a(24) =590529542053
External references
- oeis: A026084