a(n) = number |fdw(P,(n))| of entangled P-words with s=2.

A211309

a(n) = number |fdw(P,(n))| of entangled P-words with s=2.

Terms

    a(0) =1a(1) =4a(2) =60a(3) =1776a(4) =84720a(5) =5876640a(6) =556466400a(7) =68882446080

External references