Triangle read by rows: expansion of p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n - 3)*Sum[Binomial[n, m]*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].

A146767

Triangle read by rows: expansion of p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n - 3)*Sum[Binomial[n, m]*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =1a(6) =1a(7) =9a(8) =9a(9) =1a(10) =1a(11) =20a(12) =30a(13) =20a(14) =1a(15) =1a(16) =45a(17) =90a(18) =90a(19) =45a(20) =1a(21) =1a(22) =102a(23) =255a(24) =340a(25) =255a(26) =102a(27) =1a(28) =1a(29) =231

External references