Number of arrays of n integers in -3..3 with sum zero and equal numbers of elements greater than zero and less than zero.

A201806

Number of arrays of n integers in -3..3 with sum zero and equal numbers of elements greater than zero and less than zero.

Terms

    a(0) =1a(1) =7a(2) =19a(3) =151a(4) =631a(5) =4621a(6) =23857a(7) =164599a(8) =948871a(9) =6359617a(10) =38944357a(11) =258107389a(12) =1636264813a(13) =10819063087a(14) =70033892299a(15) =463844386999

External references