Number of arrays of 2n nondecreasing integers in -3..3 with sum zero and equal numbers greater than zero and less than zero.

A203286

Number of arrays of 2n nondecreasing integers in -3..3 with sum zero and equal numbers greater than zero and less than zero.

Terms

    a(0) =4a(1) =12a(2) =28a(3) =57a(4) =104a(5) =176a(6) =280a(7) =425a(8) =620a(9) =876a(10) =1204a(11) =1617a(12) =2128a(13) =2752a(14) =3504a(15) =4401a(16) =5460a(17) =6700a(18) =8140a(19) =9801a(20) =11704a(21) =13872a(22) =16328a(23) =19097a(24) =22204a(25) =25676a(26) =29540a(27) =33825a(28) =38560a(29) =43776

External references