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A229652 Cogrowth function of the group Baumslag-Solitar(10,10). 10
1, 4, 28, 232, 2092, 19864, 195352, 1970896, 20275660, 211823800, 2240795848, 23951289564, 258255473032, 2805534386256, 30675481454184, 337306578693652, 3727580774618060, 41376921517941032, 461122691909043112, 5157400529078643552 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

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(10,10)=<a,t | ta^{10}=a^{10}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

EXAMPLE

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

CROSSREFS

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

Sequence in context: A199579 A089023 A035610 * A229651 A229650 A229649

Adjacent sequences:  A229649 A229650 A229651 * A229653 A229654 A229655

KEYWORD

nonn,walk

AUTHOR

Murray Elder, Sep 28 2013

STATUS

approved

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Last modified July 5 17:29 EDT 2020. Contains 335473 sequences. (Running on oeis4.)