directly from Neil's EIS, no understanding involved: (-1)^(n+1) 4/EulerE[2n-1,1] == Pi^(2n)/(Gamma[2n]*(1-2^(-2n))*Zeta[2n]) cfr. A002425 , A037239, A058940 It should be proved by an 'enlightened'. Wouter Meeussen tel +32 (0)51 33 21 24 fax +32 (0)51 33 21 75 wouter.meeussen at vandemoortele.com