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

A187979

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

Terms

    a(0) =0a(1) =2a(2) =7a(3) =30a(4) =144a(5) =597a(6) =2742a(7) =12148a(8) =54696a(9) =247482a(10) =1120330a(11) =5099759a(12) =23249035a(13) =106285418a(14) =486878283a(15) =2234333944a(16) =10271022863a(17) =47283130811a(18) =217962771486

External references