OFFSET
1,2
COMMENTS
Conjecture: this is also the integer sequence A202367 up to sign. These numbers show up in the formula for eigenvectors of Adams operations on the K-theory of unitary groups.
LINKS
C.-K. Fok, Adams operations on classical compact Lie groups, preprint.
EXAMPLE
p_n(x):=coefficient of t^{2n} of the Maclaurin series of (t/sinh(t))^x
p_0(x)=1
p_1(x)=-x/6
p_2(x)=x(5x+2)/360
p_3(x)=-(35x^3+42x^2+16x)/45360
p_4(x)=175x^4+420x^3+404x^2+144x/5443200
p_5(x)=-(385x^5+1540x^4+2684x^3+2288x^2+768x)/359251200
MATHEMATICA
a[n_] := Module[{c}, c = SeriesCoefficient[(t/Sinh[t])^x, {t, 0, 2(n-1)}] // Together; Sign[Numerator[c /. x -> 1]] Denominator[c]];
Table[a[n], {n, 1, 17}] (* Updated by Jean-François Alcover, Feb 15 2019 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Chi-Kwong Fok, Sep 14 2015
EXTENSIONS
Sign added
STATUS
approved