The number of integer sequences of length d = 2n+1 such that the sum of the terms is 0 and the sum of the absolute values of the terms is d-1.
A156554
The number of integer sequences of length d = 2n+1 such that the sum of the terms is 0 and the sum of the absolute values of the terms is d-1.
Terms
- a(0) =1a(1) =6a(2) =110a(3) =2562a(4) =66222a(5) =1815506a(6) =51697802a(7) =1511679210a(8) =45076309166
External references
- oeis: A156554