Number of arrays of n integers in -2..2 with sum zero and equal numbers of elements greater than zero and less than zero.
A201805
Number of arrays of n integers in -2..2 with sum zero and equal numbers of elements greater than zero and less than zero.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =13a(4) =61a(5) =221a(6) =1001a(7) =4145a(8) =18733a(9) =82381a(10) =375745a(11) =1703945a(12) =7858225a(13) =36279985a(14) =168992045a(15) =789433013a(16) =3707816333a(17) =17467638925a(18) =82599195809a(19) =391645961993
External references
- oeis: A201805