a(n) = rf(n, n+2)/(n+2)! - rf(n, n)/n!, rf the rising factorial A265609.

A265610

a(n) = rf(n, n+2)/(n+2)! - rf(n, n)/n!, rf the rising factorial A265609.

Terms

    a(0) =-1a(1) =0a(2) =2a(3) =11a(4) =49a(5) =204a(6) =825a(7) =3289a(8) =13013a(9) =51272a(10) =201552a(11) =791350a(12) =3105322a(13) =12183560a(14) =47805615a(15) =187623765a(16) =736618125a(17) =2893125840a(18) =11367801060a(19) =44686512090a(20) =175739405790a(21) =691437981000

External references