Number of arrays of -4..4 integers x(1..n) with every x(i) in a subsequence of length 1, 2 or 3 with sum zero.
A193698
Number of arrays of -4..4 integers x(1..n) with every x(i) in a subsequence of length 1, 2 or 3 with sum zero.
Terms
- a(0) =1a(1) =9a(2) =69a(3) =317a(4) =1741a(5) =9385a(6) =50035a(7) =268453a(8) =1438203a(9) =7705011a(10) =41284941a(11) =221198177a(12) =1185157449a(13) =6349965025a(14) =34022467117a(15) =182289038899a(16) =976686732167
External references
- oeis: A193698