a(1) = 1, a(2) = 3, a(n+2) = 3*a(n+1) + (n+1)^2*a(n).

A142979

a(1) = 1, a(2) = 3, a(n+2) = 3*a(n+1) + (n+1)^2*a(n).

Terms

    a(0) =1a(1) =3a(2) =13a(3) =66a(4) =406a(5) =2868a(6) =23220a(7) =210192a(8) =2116656a(9) =23375520a(10) =281792160a(11) =3673814400a(12) =51599514240a(13) =775673176320

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