Number of positive words of length n in the monoid Br_5 of positive braids on 6 strands.

A097552

Number of positive words of length n in the monoid Br_5 of positive braids on 6 strands.

Terms

    a(0) =1a(1) =5a(2) =20a(3) =67a(4) =209a(5) =630a(6) =1873a(7) =5540a(8) =16357a(9) =48265a(10) =142387a(11) =420027a(12) =1239006a(13) =3654820a(14) =10780958a(15) =31801551a(16) =93807834a(17) =276713194a(18) =816245143a(19) =2407749755a(20) =7102350204a(21) =20950424039a(22) =61799299470a(23) =182294802589a(24) =537730934397

External references