a(n) = [x^n] 2/(3*sqrt(4*x^2 + 1) + 6*x - 1). Alternating row sums of A375025.

Terms

a(0) =1a(1) =-3a(2) =6a(3) =-9a(4) =12a(5) =-18a(6) =30a(7) =-45a(8) =60a(9) =-90a(10) =156a(11) =-234a(12) =288a(13) =-432a(14) =846a(15) =-1269a(16) =1260a(17) =-1890a(18) =4980a(19) =-7470a(20) =3912a(21) =-5868a(22) =33996a(23) =-50994a(24) =-11688a(25) =17532a(26) =285720a(27) =-428580a(28) =-471480a(29) =707220