Convolution of Catalan numbers A000108 with Catalan numbers but C(0)=1 replaced by 3.

A038629

Convolution of Catalan numbers A000108 with Catalan numbers but C(0)=1 replaced by 3.

Terms

    a(0) =3a(1) =4a(2) =9a(3) =24a(4) =70a(5) =216a(6) =693a(7) =2288a(8) =7722a(9) =26520a(10) =92378a(11) =325584a(12) =1158924a(13) =4160240a(14) =15043725a(15) =54747360a(16) =200360130a(17) =736928280a(18) =2722540590a(19) =10098646800a(20) =37594507860a(21) =140415097680a(22) =526024740930

External references