Congruence E_p = -p/2 (mod p**2): verification
primes: all odd primes < 200, and 251, 307, 401 (48 primes)
  ok  p=3: all steps and E_p = -p/2 mod p**2   [   0.0 s]
  ok  p=5: all steps and E_p = -p/2 mod p**2   [   0.0 s]
  ok  p=7: all steps and E_p = -p/2 mod p**2   [   0.0 s]
  ok  p=101: all steps and E_p = -p/2 mod p**2   [   1.2 s]
  ok  p=199: all steps and E_p = -p/2 mod p**2   [  14.3 s]
  ok  p=251: all steps and E_p = -p/2 mod p**2   [  16.8 s]
  ok  p=307: all steps and E_p = -p/2 mod p**2   [  21.7 s]
  ok  p=401: all steps and E_p = -p/2 mod p**2   [  32.9 s]
  all 48 primes passed
  primes in the range with E_p = -p/2 even modulo p**3: [3, 13]
ALL CHECKS PASSED