A229647 Cogrowth function of the group Baumslag-Solitar(5,5).

1, 4, 28, 232, 2092, 19864, 195376, 1971932, 20303084, 212400232, 2251379688, 24129199208, 261067326544, 2848016992032, 31295785633532, 346126420439512, 3850363854970476, 43057199315715676, 483795646775017312, 5459770924922887392

Offset: 0

Author

Murray Elder, Sep 27 2013

Keywords

• nonn
• walk

Comments

a(n) is the number of words of length 2n in the letters a,a^{-1},t,t^{-1} that equal the identity of the group BS(5,5)=.

Examples

			For n=1 there are 4 words of length 2 equal to the identity: aa^{-1}, a^{-1}a, tt^{-1}, t^{-1}t.
		

Links

• Murray Elder, Table of n, a(n) for n = 0..50
• M. Elder, A. Rechnitzer, E. J. Janse van Rensburg, T. Wong, The cogrowth series for BS(N,N) is D-finite
• Index entries for sequences related to groups

Crossrefs

The cogrowth sequences for BS(N,N) for N = 1..10 are A002894, A229644, A229645, A229646, A229647, A229648, A229649, A229650, A229651, A229652.