968383680827domain: NAppears in sequencesDenominator of Pi^(2n)/(Gamma(2n)*(1-2^(-2n))*zeta(2n)).at n=11A002425Numerators of Euler twin numbers Et(n).at n=24A238235a(n) = (4^n*(Z(-n, 1/4) - Z(-n, 3/4)) + Z(-n, 1)*(2^(n+1)-1))*A171977(n+1), where Z(n, c) is the Hurwitz zeta function.at n=23A335955