title: Count Even Length Binary Sequences With Same Sum Of First And Second Half Bits 1
signature: countEvenLengthBinarySequencesWithSameSumOfFirstAndSecondHalfBits1 :: Integer -> Double
  countEvenLengthBinarySequencesWithSameSumOfFirstAndSecondHalfBits1 n = 
test_code: import Text.Printf
  import Control.Exception (catch, SomeException)
  import Data.Typeable
  import qualified Data.List as List
  import qualified Data.Map as Map
  import qualified Data.Set as Set
  
  -- SOLUTION CODE
  -- ============================================
  
  PLACEHOLDER_CODE_BODY
  
  -- TESTING CODE 
  -- ============================================
  validateSolution :: Double -> Double -> Bool
  validateSolution actual expected = do
      (abs (actual-expected)) < 1e-09
  
  driver :: Integer -> Double -> String
  driver n expected = do
      if (validateSolution (PLACEHOLDER_FN_NAME n) expected)
          then "PASSED"
      else "FAILED"
  
  main = do
      printf "TEST-0...%s\n" (driver (25) (126410606437752.0) )
  
      printf "TEST-1...%s\n" (driver (18) (9075135300.0) )
  
      printf "TEST-2...%s\n" (driver (17) (2333606220.0) )
  
      printf "TEST-3...%s\n" (driver (8) (12870.0) )
  
      printf "TEST-4...%s\n" (driver (8) (12870.0) )
  
source_py: def count_even_length_binary_sequences_with_same_sum_of_first_and_second_half_bits_1(n):
      nCr = 1
      res = 1
      for r in range(1, (n + 1)):
          nCr = ((nCr * ((n + 1) - r)) / r)
          res += (nCr * nCr)
      return res
source_cpp: int count_even_length_binary_sequences_with_same_sum_of_first_and_second_half_bits_1(int n) {
    int nCr = 1, res = 1;
    for ( int r = 1;
    r <= n;
    r ++ ) {
      nCr = ( nCr * ( n + 1 - r ) ) / r;
      res += nCr * nCr;
    }
    return res;
  }