Triangle read by rows: T(n, k) = 2^k - binomial(n, k+1) + 2^(n-k) - binomial(n, n-k+1).

Terms

a(0) =2a(1) =2a(2) =2a(3) =3a(4) =2a(5) =3a(6) =6a(7) =2a(8) =2a(9) =6a(10) =13a(11) =3a(12) =0a(13) =3a(14) =13a(15) =28a(16) =7a(17) =-3a(18) =-3a(19) =7a(20) =28a(21) =59a(22) =18a(23) =-6a(24) =-14a(25) =-6a(26) =18a(27) =59a(28) =122a(29) =44