Number of nondecreasing integer sequences of length 24 with sum zero and sum of absolute values 2n.

Terms

a(0) =1a(1) =4a(2) =9a(3) =25a(4) =49a(5) =121a(6) =225a(7) =484a(8) =900a(9) =1764a(10) =3136a(11) =5929a(12) =10198a(13) =18207a(14) =30902a(15) =53112a(16) =87477a(17) =146280a(18) =235352a(19) =382268a(20) =603867a(21) =955729a(22) =1479496a(23) =2296934a(24) =3491460a(25) =5309663a(26) =7948581a(27) =11878002a(28) =17501717a(29) =25755983