Convolution of A115140 with itself.

Terms

a(0) =1a(1) =-2a(2) =-1a(3) =-2a(4) =-5a(5) =-14a(6) =-42a(7) =-132a(8) =-429a(9) =-1430a(10) =-4862a(11) =-16796a(12) =-58786a(13) =-208012a(14) =-742900a(15) =-2674440a(16) =-9694845a(17) =-35357670a(18) =-129644790a(19) =-477638700a(20) =-1767263190a(21) =-6564120420a(22) =-24466267020a(23) =-91482563640a(24) =-343059613650