a(n) is the number of trivial braids on 3 strands which are products of n generators a, b, where a = sigma_1 sigma_2 sigma_1 and b = sigma_1 sigma_2.

A358653

a(n) is the number of trivial braids on 3 strands which are products of n generators a, b, where a = sigma_1 sigma_2 sigma_1 and b = sigma_1 sigma_2.

Terms

    a(0) =1a(1) =0a(2) =4a(3) =0a(4) =28a(5) =10a(6) =244a(7) =210a(8) =2412a(9) =3366a(10) =26014a(11) =49456a(12) =299452a(13) =701818a(14) =3624478

External references