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A003706 E.g.f. sin(tan(x)), zeros omitted.
(Formerly M3176)
4
1, 1, -3, -275, -15015, -968167, -77000363, -7433044411, -843598411471, -107426835190735, -14072980460605907, -1424712499632406371, 164163646840636339593, 237037449673450822122569 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Vladimir Kruchinin, Compositae and their properties, arXiv:1103.2582

FORMULA

a(n)=b(2*n-1), b(n)=sum(k=1..n, ((-1)^(n-k)+1)*sum(j=k..n, binomial(j-1,k-1)*j!*2^(n-j-1)*(-1)^((n+k)/2+j)*stirling2(n,j))*((-1)^((k+3)/2)-(-1)^((3*k+3)/2))/(2*k!)); [From Vladimir Kruchinin kru(AT)ie.tusur.ru, Apr 23 2011]

a(n):=sum(m=0..n, sum(j=0..2*n-2*m, binomial(j+2*m,2*m)*(j+2*m+1)!*2^(2*n-2*m-j)*(-1)^(n+j)* stirling2(2*n+1,j+2*m+1))/((2*m+1)!)); [From Vladimir Kruchinin kru(AT)ie.tusur.ru, Jan 21 2012]

MATHEMATICA

Sin[ Tan[ x ] ] (* Odd Part *)

PROG

(Maxima)

a(n):=b(2*n-1);

b(n):=sum(((-1)^(n-k)+1)*sum(binomial(j-1, k-1)*j!*2^(n-j-1)*(-1)^((n+k)/2+j)*stirling2(n, j), j, k, n)*((-1)^((k+3)/2)-(-1)^((3*k+3)/2))/(2*k!), k, 1, n); [From Vladimir Kruchinin kru(AT)ie.tusur.ru, Apr 23 2011]

a(n):=sum(sum(binomial(j+2*m, 2*m)*(j+2*m+1)!*2^(2*n-2*m-j)*(-1)^(n+j)*stirling2(2*n+1, j+2*m+1), j, 0, 2*n-2*m)/((2*m+1)!), m, 0, n); [From Vladimir Kruchinin kru(AT)ie.tusur.ru, Jan 21 2012]

CROSSREFS

Sequence in context: A171358 A115477 A051365 * A068250 A096126 A057599

Adjacent sequences:  A003703 A003704 A003705 * A003707 A003708 A003709

KEYWORD

sign

AUTHOR

R. H. Hardin (rhhardin(AT)att.net), Simon Plouffe (simon.plouffe(AT)gmail.com)

EXTENSIONS

Corrected name, Joerg Arndt, Apr 23 2011.

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Last modified February 17 21:13 EST 2012. Contains 206085 sequences.