Main diagonal of A279928.

Terms

a(0) =1a(1) =-1a(2) =-1a(3) =-1a(4) =23a(5) =-51a(6) =35a(7) =-197a(8) =1367a(9) =-3889a(10) =7649a(11) =-26258a(12) =112739a(13) =-350676a(14) =939623a(15) =-3063201a(16) =11022167a(17) =-35276497a(18) =106320311a(19) =-344831533a(20) =1164544273a(21) =-3765456206a(22) =11890410454a(23) =-38631658591a(24) =127610160227a(25) =-414671018176