A diagonal of irregular triangle A201949.

A201953

A diagonal of irregular triangle A201949.

Terms

    a(0) =1a(1) =3a(2) =15a(3) =90a(4) =629a(5) =5019a(6) =45030a(7) =448776a(8) =4919321a(9) =58825415a(10) =762089899a(11) =10633219662a(12) =158974192987

External references