# Python program for OEIS A237500
# by Michael S. Branicky, Feb 06 2021

from numba import njit
@njit
def a(n):
  fullmask = (1<<(2*n)) - 1
  lasthalfmask = (1<<n) - 1
  firsthalfmask = lasthalfmask << n
  first1 = (1 <<(2*n-1))
  c = 0
  for i in range(2**(2*n-1)):
    k = first1 + i 
    complement = fullmask ^ k
    complement1 = (complement & firsthalfmask) >> n
    complement2 = complement & lasthalfmask
    comp1_is_in = False
    for j in range(n+1):
      shiftedmask = lasthalfmask << j
      if ((shiftedmask & k) >> j) ^ complement1 == 0:
        comp1_is_in = True
        break
    if not comp1_is_in:
      continue
    comp2_is_in = False
    for j in range(n+1):
      shiftedmask = lasthalfmask << j
      if ((shiftedmask & k) >> j) ^ complement2 == 0:
        comp2_is_in = True
        break
    if not comp2_is_in:
      continue   
    c += 1
  return 2*c

from time import time
time0 = time()

for n in range(1, 101):
  an = a(n)
  print(n, an, time()-time0, flush=True)