function [ n_data, n, c ] = omega_values ( n_data )

%*****************************************************************************80
%
%% OMEGA_VALUES returns some values of the OMEGA function.
%
%  Discussion:
%
%    In Mathematica, the function can be evaluated by
%
%      Length [ FactorInteger [ n ] ]
%
%  First values:
%
%     N   OMEGA(N)
%
%     1    0
%     2    1
%     3    1
%     4    1
%     5    1
%     6    2
%     7    1
%     8    1
%     9    1
%    10    2
%    11    1
%    12    2
%    13    1
%    14    2
%    15    2
%    16    1
%    17    1
%    18    2
%    19    1
%    20    2
%
%  Formula:
%
%    If N = 1, then
%
%      OMEGA(N) = 0
%
%    else if the prime factorization of N is
%
%      N = P1^E1 * P2^E2 * ... * PM^EM,
%
%    then
%
%      OMEGA(N) = M
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    17 April 2013
%
%  Author:
%
%    John Burkardt
%
%  Reference:
%
%    Milton Abramowitz and Irene Stegun,
%    Handbook of Mathematical Functions,
%    US Department of Commerce, 1964.
%
%    Stephen Wolfram,
%    The Mathematica Book,
%    Fourth Edition,
%    Wolfram Media / Cambridge University Press, 1999.
%
%  Parameters:
%
%    Input/output, integer N_DATA.  The user sets N_DATA to 0 before the
%    first call.  On each call, the routine increments N_DATA by 1, and
%    returns the corresponding data; when there is no more data, the
%    output value of N_DATA will be 0 again.
%
%    Output, integer N, the argument of the OMEGA function.
%
%    Output, integer C, the value of the OMEGA function.
%
  n_max = 23;

  c_vec = [ ...
      0,   1,   1,   1,   1, ...
      2,   1,   1,   1,   2, ...
      3,   1,   4,   4,   3, ...
      1,   5,   2,   2,   1, ...
      6,   7,   8 ];

  n_vec = [ ...
           1, ...
           2, ...
           3, ...
           4, ...
           5, ...
           6, ...
           7, ...
           8, ...
           9, ...
          10, ...
          30, ...
         101, ...
         210, ...
        1320, ...
        1764, ...
        2003, ...
        2310, ...
        2827, ...
        8717, ...
       12553, ...
       30030, ...
      510510, ...
     9699690 ];

  if ( n_data < 0 )
    n_data = 0;
  end

  n_data = n_data + 1;

  if ( n_max < n_data )
    n_data = 0;
    n = 0;
    c = 0;
  else
    n = n_vec(n_data);
    c = c_vec(n_data);
  end

  return
end
