Coefficient of x^(n-1) in Product_{k=1..n} (k + x + (n+1-k)*x^2), for n >= 1.

A322234

Coefficient of x^(n-1) in Product_{k=1..n} (k + x + (n+1-k)*x^2), for n >= 1.

Terms

    a(0) =1a(1) =3a(2) =32a(3) =210a(4) =3594a(5) =37457a(6) =896412a(7) =12899520a(8) =398293065a(9) =7333821066a(10) =277832923686

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