Repeated terms in A131771; a(n) = A131770( (n+1)*(n+2)/2 - 1 ) for n>=0.

A131786

Repeated terms in A131771; a(n) = A131770( (n+1)*(n+2)/2 - 1 ) for n>=0.

Terms

    a(0) =1a(1) =4a(2) =20a(3) =104a(4) =592a(5) =3592a(6) =23212a(7) =158652a(8) =1141964a(9) =8621820a(10) =68063300a(11) =560324488a(12) =4799515756a(13) =42690098440a(14) =393605305676

External references