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A046983
Denominators of Taylor series for tan(x + Pi/4).
4
1, 1, 1, 3, 3, 15, 45, 315, 63, 2835, 14175, 155925, 93555, 6081075, 42567525, 638512875, 127702575, 10854718875, 97692469875, 1856156927625, 371231385525, 194896477400625, 2143861251406875, 2900518163668125, 2275791174570375
OFFSET
0,4
REFERENCES
G. W. Caunt, Infinitesimal Calculus, Oxford Univ. Press, 1914, p. 477.
EXAMPLE
1 + 2*x + 2*x^2 + (8/3)*x^3 + (10/3)*x^4 + (64/15)*x^5 + (244/45)*x^6 + ...
MAPLE
A046983 := proc(n)
coeftayl(tan(x+Pi/4), x=0, n) ;
denom(%) ;
end proc: # R. J. Mathar, Jan 22 2017
MATHEMATICA
nmax = 24; t[0, 1] = 1; t[0, _] = 0; t[n_, k_] := t[n, k] = (k-1)*t[n-1, k-1] + (k+1)*t[n-1, k+1]; Denominator[ Table[ Sum[ t[n, k]/n!, {k, 0, n+1}], {n, 0, nmax} ]] (* Jean-François Alcover, Nov 09 2011 *)
CoefficientList[Series[Tan[x+Pi/4], {x, 0, 30}], x]//Denominator (* Harvey P. Dale, Sep 05 2023 *)
CROSSREFS
Cf. A046982.
Sequence in context: A352802 A160639 A280781 * A067655 A209430 A160624
KEYWORD
nonn,frac,easy,nice
STATUS
approved