Number of nondecreasing arrangements of n numbers x(i) in -(n-1)..(n-1) with the sum of sign(x(i))*x(i)^2 zero.

A187994

Number of nondecreasing arrangements of n numbers x(i) in -(n-1)..(n-1) with the sum of sign(x(i))*x(i)^2 zero.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =12a(4) =25a(5) =106a(6) =376a(7) =1670a(8) =7315a(9) =35808a(10) =176971a(11) =910940a(12) =4782220a(13) =25663080a(14) =139884020a(15) =773939566a(16) =4334475055a(17) =24546800088a(18) =140363450663a(19) =809676156506

External references