Number of nondecreasing arrangements of n numbers in -(n-1)..(n-1) with sum zero and not more than two numbers equal.
A188228
Number of nondecreasing arrangements of n numbers in -(n-1)..(n-1) with sum zero and not more than two numbers equal.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =15a(4) =58a(5) =245a(6) =1082a(7) =5020a(8) =24040a(9) =118154a(10) =592332a(11) =3019280a(12) =15604848a(13) =81614541a(14) =431227650a(15) =2298833499a(16) =12350952158a(17) =66818754504a(18) =363727676848
External references
- oeis: A188228