Number of Catalan objects fixed by two-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).
A079223
Number of Catalan objects fixed by two-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =11a(5) =26a(6) =66a(7) =161a(8) =420a(9) =1093a(10) =2916a(11) =7819a(12) =21304a(13) =58321a(14) =161233a(15) =448090a(16) =1253252a(17) =3521389a(18) =9941693a(19) =28175716a(20) =80152141a(21) =228747967a(22) =654817275a(23) =1879602446a(24) =5408974390a(25) =15601662378a(26) =45098766532a(27) =130624550412
External references
- oeis: A079223