p-INVERT of the squares (A000290), where p(S) = 1 + S - S^2.

Terms

a(0) =-1a(1) =-2a(2) =4a(3) =21a(4) =30a(5) =11a(6) =80a(7) =622a(8) =2055a(9) =4584a(10) =10711a(11) =34354a(12) =115480a(13) =341213a(14) =934750a(15) =2640483a(16) =7874188a(17) =23564242a(18) =68738591a(19) =198108496a(20) =575654335a(21) =1688669686a(22) =4951141372a(23) =14443935957a(24) =42064267934a(25) =122731975243a(26) =358682023576