B_(2 n) = A_n - sum_p^(2 n) [(2 n)/(p - 1) element Z ∧ p element P]/p for A_n element Z Denominator[B_(2 n)] = product_(k=1)^(2 n + 1)( piecewise | k | (k element P and (2 n)/(-1 + k) element Z) 1 | otherwise) for (n element Z and n>=1)