a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 6. Also a(n) = T(n,n-4), where T is the array in A026323.
A026329
a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 6. Also a(n) = T(n,n-4), where T is the array in A026323.
Terms
- a(0) =1a(1) =5a(2) =21a(3) =77a(4) =266a(5) =882a(6) =2849a(7) =9031a(8) =28236a(9) =87360a(10) =268086a(11) =817362a(12) =2479008a(13) =7486528a(14) =22529250a(15) =67598086a(16) =202325585a(17) =604317021a(18) =1801836652a(19) =5364359966a(20) =15950297370a(21) =47375004170a(22) =140581490790a(23) =416834841150
External references
- oeis: A026329