

A029698


Number of words of length 2n in the 10 transpositions of S[5] equivalent to the identity.


1



10, 340, 20860, 1770940, 169271260, 16731772540, 1668294277660, 166707356798140, 16667683919380060, 1666692097982207740, 166667302449546018460, 16666682561238613761340, 1666667064030965197232860, 166666676600774129343618940, 16666666915019353231241663260
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OFFSET

1,1


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..300
Index entries for linear recurrences with constant coefficients, signature (129,3000,10000).


FORMULA

a(n) = (25*4^n+16*25^n +100^n)/60.
a(n) = 129*a(n1)3000*a(n2)+10000*a(3).  Colin Barker, May 28 2015
G.f.: 10*x*(700*x^295*x+1) / ((4*x1)*(25*x1)*(100*x1)).  Colin Barker, May 28 2015


PROG

(MAGMA) [(25*4^n+16*25^n +100^n)/60: n in [1..15]]; // Vincenzo Librandi, Jun 30 2011
(PARI) Vec(10*x*(700*x^295*x+1) / ((4*x1)*(25*x1)*(100*x1)) + O(x^100)) \\ Colin Barker, May 28 2015


CROSSREFS

Sequence in context: A288684 A046747 A006426 * A197598 A197982 A217506
Adjacent sequences: A029695 A029696 A029697 * A029699 A029700 A029701


KEYWORD

nonn,easy


AUTHOR

Paolo Dominici (pl.dm(AT)libero.it)


STATUS

approved



