Number of blocks in all RNA secondary structures with n nodes (an RNA secondary structure can be viewed as a restricted noncrossing partition).

A110320

Number of blocks in all RNA secondary structures with n nodes (an RNA secondary structure can be viewed as a restricted noncrossing partition).

Terms

    a(0) =1a(1) =2a(2) =5a(3) =13a(4) =32a(5) =80a(6) =201a(7) =505a(8) =1273a(9) =3217a(10) =8146a(11) =20668a(12) =52531a(13) =133726a(14) =340909a(15) =870213a(16) =2223958a(17) =5689807a(18) =14571335a(19) =37350585a(20) =95821071a(21) =246015677a(22) =632088930a(23) =1625119218a(24) =4180845277a(25) =10762096850a(26) =27718352411a(27) =71426753423a(28) =184146711578

External references