function st = state_neighbors ( )

%*****************************************************************************80
%
%% state_neighbors() returns an array of pairs of US state neighbors.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    04 November 2022
%
%  Author:
%
%    John Burkardt
%
%  Output:
%
%    integer st(210,2): the indices of pairs of state neighbors. 
%
  st = [ ...
    1,9; ...
    1,10; ...
    1,42; ...
    1,24; ...
    3,31; ...
    3,44; ...
    3,28; ...
    3,5; ...
    4,18; ...
    4,24; ...
    4,42; ...
    4,25; ...
    4,36; ...
    4,43; ...
    5,3; ...
    5,28; ...
    5,37; ...
    6,31; ...
    6,36; ...
    6,16; ...
    6,27; ...
    6,50; ...
    6,44; ...
    7,39; ...
    7,21; ...
    7,32; ...
    8,30; ...
    8,38; ...
    8,20; ...
    9,10; ...
    9,1; ...
    10,40; ...
    10,33; ...
    10,42; ...
    10,1; ...
    10,9; ...
    12,47; ...
    12,37; ...
    12,28; ...
    12,44; ...
    12,50; ...
    12,26; ...
    13,49; ...
    13,15; ...
    13,25; ...
    13,17; ...
    13,14; ...
    14,13; ...
    14,17; ...
    14,35; ...
    14,22; ...
    15,23; ...
    15,41; ...
    15,27; ...
    15,25; ...
    15,13; ...
    15,49; ...
    16,36; ...
    16,25; ...
    16,27; ...
    16,6; ...
    17,42; ...
    17,46; ...
    17,48; ...
    17,35; ...
    17,14; ...
    17,13; ...
    17,25; ...
    18,24; ...
    18,4; ...
    18,43; ...
    19,29; ...
    20,8; ...
    20,38; ...
    20,48; ...
    20,46; ...
    21,29; ...
    21,45; ...
    21,32; ...
    21,7; ...
    21,39; ...
    22,49; ...
    22,14; ...
    22,35; ...
    23,34; ...
    23,41; ...
    23,15; ...
    23,49; ...
    24,1; ...
    24,42; ...
    24,4; ...
    24,18; ...
    25,4; ...
    25,42; ...
    25,17; ...
    25,13; ...
    25,15; ...
    25,27; ...
    25,16; ...
    25,36; ...
    26,12; ...
    26,50; ...
    26,41; ...
    26,34; ...
    27,16; ...
    27,25; ...
    27,15; ...
    27,41; ...
    27,50; ...
    27,6; ...
    28,3; ...
    28,44; ...
    28,12; ...
    28,37; ...
    28,5; ...
    29,45; ...
    29,21; ...
    29,19; ...
    30,32; ...
    30,38; ...
    30,8; ...
    31,43; ...
    31,36; ...
    31,6; ...
    31,3; ...
    32,38; ...
    32,30; ...
    32,7; ...
    32,21; ...
    32,45; ...
    33,46; ...
    33,42; ...
    33,10; ...
    33,40; ...
    34,26; ...
    34,41; ...
    34,23; ...
    35,22; ...
    35,14; ...
    35,17; ...
    35,48; ...
    35,38; ...
    36,43; ...
    36,4; ...
    36,25; ...
    36,16; ...
    36,6; ...
    36,31; ...
    37,5; ...
    37,28; ...
    37,12; ...
    37,47; ...
    38,35; ...
    38,48; ...
    38,20; ...
    38,8; ...
    38,30; ...
    38,32; ...
    39,21; ...
    39,7; ...
    40,33; ...
    40,10; ...
    41,27; ...
    41,15; ...
    41,23; ...
    41,34; ...
    41,26; ...
    41,50; ...
    42,1; ...
    42,10; ...
    42,33; ...
    42,46; ...
    42,17; ...
    42,25; ...
    42,4; ...
    42,24; ...
    43,18; ...
    43,4; ...
    43,36; ...
    43,31; ...
    44,3; ...
    44,6; ...
    44,50; ...
    44,12; ...
    44,28; ...
    45,32; ...
    45,21; ...
    45,29; ...
    46,20; ...
    46,48; ...
    46,17; ...
    46,42; ...
    46,33; ...
    47,37; ...
    47,12; ...
    48,46; ...
    48,20; ...
    48,38; ...
    48,35; ...
    48,17; ...
    49,23; ...
    49,15; ...
    49,13; ...
    49,22; ...
    50,6; ...
    50,27; ...
    50,41; ...
    50,26; ...
    50,12; ...
    50,44 ];

  return
end
 
