OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..150
FORMULA
a(n) = (1/2)*(-1)^n*(2*n-5)!!*((4*n^2-6*n-2)+(16*n^3-24*n^2-4*n+6)*sum((-1)^(k+n)/ (2*k+1), k=0..n-1)).
MATHEMATICA
Table[(1/2)*(-1)^n*(2*n - 5)!!*((4*n^2 - 6*n - 2) + (16*n^3 - 24*n^2 - 4*n + 6)*Sum[(-1)^(k + n)/(2*k + 1), {k, 0, n - 1}]), {n, 1, 50}] (* G. C. Greubel, Jun 16 2016 *)
CROSSREFS
Equals the second column of the ED3 array A167572.
KEYWORD
easy,nonn
AUTHOR
Johannes W. Meijer, Nov 10 2009
STATUS
approved