Number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, s(1) = 1, s(n) = 2, |s(i) - s(i-1)| <= 1 for i >= 2, |s(2) - s(1)| = 1, |s(3) - s(2)| = 1 if s(2) = 1. Also T(n,n-2), where T is the array in A026268.
A026288
Number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, s(1) = 1, s(n) = 2, |s(i) - s(i-1)| <= 1 for i >= 2, |s(2) - s(1)| = 1, |s(3) - s(2)| = 1 if s(2) = 1. Also T(n,n-2), where T is the array in A026268.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =14a(4) =38a(5) =104a(6) =285a(7) =784a(8) =2164a(9) =5994a(10) =16658a(11) =46442a(12) =129868a(13) =364182a(14) =1023960a(15) =2886174a(16) =8153952a(17) =23086374a(18) =65497653a(19) =186175794a(20) =530148414a(21) =1512174076a(22) =4320093569a(23) =12360382436a(24) =35414530188a(25) =101603373430a(26) =291864076387a(27) =839402336610
External references
- oeis: A026288