Number of strictly increasing arrangements of 8 nonzero numbers in -(n+6)..(n+6) with sum zero.

Terms

a(0) =137a(1) =484a(2) =1398a(3) =3528a(4) =7970a(5) =16547a(6) =32035a(7) =58595a(8) =102113a(9) =170844a(10) =275878a(11) =432018a(12) =658432a(13) =979785a(14) =1427065a(15) =2039067a(16) =2863403a(17) =3958322a(18) =5393994a(19) =7254686a(20) =9640296a(21) =12669003a(22) =16479033a(23) =21231771a(24) =27113883a(25) =34340884a(26) =43159574a(27) =53852210a(28) =66739242a(29) =82184043