Self-convolution of array T given by A026009.

Terms

a(0) =1a(1) =2a(2) =6a(3) =15a(4) =54a(5) =118a(6) =471a(7) =973a(8) =4128a(9) =8262a(10) =36481a(11) =71534a(12) =324876a(13) =627926a(14) =2911923a(15) =5568348a(16) =26241376a(17) =49767432a(18) =237550401a(19) =447567059a(20) =2158650078a(21) =4045351674a(22) =19679880649a(23) =36716551814a(24) =179920446576a(25) =334415846660