code: def twinprime_fixed(prec):
      def I(n):
          return (
              sum(
                  moebius(d) << (n // d)
                  for d in xrange(1, n + 1)
                  if not n % d
              )
              // n
          )
  
      wp = 2 * prec + 30
      res = fone
      primes = [from_rational(1, p, wp) for p in [2, 3, 5, 7]]
      ppowers = [mpf_mul(p, p, wp) for p in primes]
      n = 2
      while 1:
          a = mpf_zeta_int(n, wp)
          for i in range(4):
              a = mpf_mul(a, mpf_sub(fone, ppowers[i]), wp)
              ppowers[i] = mpf_mul(ppowers[i], primes[i], wp)
          a = mpf_pow_int(a, -I(n), wp)
          if mpf_pos(a, prec + 10, "n") == fone:
              break
          # from libmpf import to_str
          # print n, to_str(mpf_sub(fone, a), 6)
          res = mpf_mul(res, a, wp)
          n += 1
      res = mpf_mul(res, from_int(3 * 15 * 35), wp)
      res = mpf_div(res, from_int(4 * 16 * 36), wp)
      return to_fixed(res, prec)
  
imports: import math
  import sys
  from .backend import xrange
  from .backend import MPZ, MPZ_ZERO, MPZ_ONE, MPZ_THREE, gmpy
  from .libintmath import list_primes, ifac, ifac2, moebius
  from .libmpf import round_floor, round_ceiling, round_down, round_up, round_nearest, round_fast, lshift, sqrt_fixed, isqrt_fast, fzero, fone, fnone, fhalf, ftwo, finf, fninf, fnan, from_int, to_int, to_fixed, from_man_exp, from_rational, mpf_pos, mpf_neg, mpf_abs, mpf_add, mpf_sub, mpf_mul, mpf_mul_int, mpf_div, mpf_sqrt, mpf_pow_int, mpf_rdiv_int, mpf_perturb, mpf_le, mpf_lt, mpf_gt, mpf_shift, negative_rnd, reciprocal_rnd, bitcount, to_float, mpf_floor, mpf_sign, ComplexResult
  from .libelefun import constant_memo, def_mpf_constant, mpf_pi, pi_fixed, ln2_fixed, log_int_fixed, mpf_ln2, mpf_exp, mpf_log, mpf_pow, mpf_cosh, mpf_cos_sin, mpf_cosh_sinh, mpf_cos_sin_pi, mpf_cos_pi, mpf_sin_pi, ln_sqrt2pi_fixed, mpf_ln_sqrt2pi, sqrtpi_fixed, mpf_sqrtpi, cos_sin_fixed, exp_fixed
  from .libmpc import mpc_zero, mpc_one, mpc_half, mpc_two, mpc_abs, mpc_shift, mpc_pos, mpc_neg, mpc_add, mpc_sub, mpc_mul, mpc_div, mpc_add_mpf, mpc_mul_mpf, mpc_div_mpf, mpc_mpf_div, mpc_mul_int, mpc_pow_int, mpc_log, mpc_exp, mpc_pow, mpc_cos_pi, mpc_sin_pi, mpc_reciprocal, mpc_square, mpc_sub_mpf
label_desc: Use image node_id 7 for calling a global function with example usage: twinprime_fixed(prec) and returns: to_fixed, unknown