Number of nondecreasing arrangements of n numbers x(i) in -(n+5)..(n+5) with the sum of sign(x(i))*2^|x(i)| zero.
A187986
Number of nondecreasing arrangements of n numbers x(i) in -(n+5)..(n+5) with the sum of sign(x(i))*2^|x(i)| zero.
Terms
- a(0) =0a(1) =7a(2) =15a(3) =60a(4) =222a(5) =746a(6) =2742a(7) =9689a(8) =34588a(9) =124062a(10) =443469a(11) =1591177a(12) =5710783a(13) =20514746a(14) =73779819a(15) =265523140a(16) =956384656a(17) =3447285428a(18) =12433999199a(19) =44877035870a(20) =162066465738a(21) =585603996081
External references
- oeis: A187986