Number of achiral color patterns (set partitions) in a row or cycle of length n with 5 or fewer colors (subsets).

A305751

Number of achiral color patterns (set partitions) in a row or cycle of length n with 5 or fewer colors (subsets).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =12a(6) =30a(7) =55a(8) =141a(9) =266a(10) =688a(11) =1313a(12) =3407a(13) =6532a(14) =16970a(15) =32595a(16) =84721a(17) =162846a(18) =423348a(19) =813973a(20) =2116227a(21) =4069352a(22) =10580110a(23) =20345735a(24) =52898501a(25) =101726626a(26) =264488408a(27) =508629033a(28) =1322433847a(29) =2543136972

External references