Number of arrays of -7..7 integers x(1..n) with every x(i) in a subsequence of length 1 or 2 with sum zero.

A193647

Number of arrays of -7..7 integers x(1..n) with every x(i) in a subsequence of length 1 or 2 with sum zero.

Terms

    a(0) =1a(1) =15a(2) =43a(3) =267a(4) =1065a(5) =5377a(6) =23801a(7) =113191a(8) =517371a(9) =2416835a(10) =11155313a(11) =51830017a(12) =239940625a(13) =1112996767a(14) =5157111051a(15) =23910123931a(16) =110818577241a(17) =513715752705

External references