The autosequence of the first kind between A226158(n) and A278331(n).

Terms

a(0) =0a(1) =1a(2) =1a(3) =-1a(4) =-3a(5) =3a(6) =17a(7) =-17a(8) =-155a(9) =155a(10) =2073a(11) =-2073a(12) =-38227a(13) =38227a(14) =929569a(15) =-929569a(16) =-28820619a(17) =28820619a(18) =1109652905a(19) =-1109652905a(20) =-51943281731a(21) =51943281731