Number of arrays of 4 nondecreasing integers in -n..n with sum zero and equal numbers greater than zero and less than zero.

A203292

Number of arrays of 4 nondecreasing integers in -n..n with sum zero and equal numbers greater than zero and less than zero.

Terms

    a(0) =3a(1) =6a(2) =12a(3) =21a(4) =35a(5) =54a(6) =80a(7) =113a(8) =155a(9) =206a(10) =268a(11) =341a(12) =427a(13) =526a(14) =640a(15) =769a(16) =915a(17) =1078a(18) =1260a(19) =1461a(20) =1683a(21) =1926a(22) =2192a(23) =2481a(24) =2795a(25) =3134a(26) =3500a(27) =3893a(28) =4315a(29) =4766

External references