Average month = ( n1*29 + n2*30 ) / ( n1 + n2 ) days
Synodic month 2000 = 29.530589, synodic month 3000 = 29.530583

   n1   n2 n1+n2 n2-n1    av. mon.   diff.2000   diff.3000
   23   26    49     3   29.530612   0.000079%   0.000099%
  169  191   360    22   29.530556  -0.000113%  -0.000093%
  192  217   409    25   29.530562  -0.000090%  -0.000070%
  215  243   458    28   29.530568  -0.000072%  -0.000052%
  238  269   507    31   29.530572  -0.000058%  -0.000037%
  261  295   556    34   29.530576  -0.000046%  -0.000025%
  284  321   605    37   29.530579  -0.000036%  -0.000015%
  307  347   654    40   29.530581  -0.000027%  -0.000007%
  330  373   703    43   29.530583  -0.000020%   0.000001%
  353  399   752    46   29.530585  -0.000013%   0.000007%
  361  408   769    47   29.530559  -0.000101%  -0.000081%
  376  425   801    49   29.530587  -0.000008%   0.000013%
  399  451   850    52   29.530588  -0.000003%   0.000018%
  407  460   867    53   29.530565  -0.000081%  -0.000060%
  422  477   899    55   29.530590   0.000002%   0.000022%
  445  503   948    58   29.530591   0.000006%   0.000026%
  453  512   965    59   29.530570  -0.000065%  -0.000044%
  468  529   997    61   29.530592   0.000009%   0.000030%
  491  555  1046    64   29.530593   0.000013%   0.000033%
  499  564  1063    65   29.530574  -0.000051%  -0.000031%
  514  581  1095    67   29.530594   0.000016%   0.000036%
  530  599  1129    69   29.530558  -0.000105%  -0.000085%
  537  607  1144    70   29.530594   0.000018%   0.000039%
  545  616  1161    71   29.530577  -0.000040%  -0.000020%
  553  625  1178    72   29.530560  -0.000097%  -0.000077%
  560  633  1193    73   29.530595   0.000021%   0.000041%
  583  659  1242    76   29.530596   0.000023%   0.000043%
  591  668  1259    77   29.530580  -0.000031%  -0.000011%
  599  677  1276    78   29.530564  -0.000084%  -0.000063%
  606  685  1291    79   29.530596   0.000025%   0.000046%
  622  703  1325    81   29.530566  -0.000078%  -0.000057%
  629  711  1340    82   29.530597   0.000027%   0.000047%
  637  720  1357    83   29.530582  -0.000023%  -0.000003%
  652  737  1389    85   29.530598   0.000029%   0.000049%
  653  738  1391    85   29.530554  -0.000120%  -0.000100%
  668  755  1423    87   29.530569  -0.000067%  -0.000047%
  675  763  1438    88   29.530598   0.000031%   0.000051%
  683  772  1455    89   29.530584  -0.000016%   0.000004%
  691  781  1472    90   29.530571  -0.000062%  -0.000042%
  698  789  1487    91   29.530599   0.000032%   0.000053%
  699  790  1489    91   29.530557  -0.000107%  -0.000087%
  721  815  1536    94   29.530599   0.000034%   0.000054%
  729  824  1553    95   29.530586  -0.000010%   0.000010%
  737  833  1570    96   29.530573  -0.000053%  -0.000033%
  744  841  1585    97   29.530599   0.000035%   0.000055%
  745  842  1587    97   29.530561  -0.000095%  -0.000075%
  760  859  1619    99   29.530574  -0.000049%  -0.000029%
  767  867  1634   100   29.530600   0.000036%   0.000057%
  775  876  1651   101   29.530588  -0.000005%   0.000015%
  790  893  1683   103   29.530600   0.000038%   0.000058%
  791  894  1685   103   29.530564  -0.000085%  -0.000065%
  806  911  1717   105   29.530577  -0.000042%  -0.000022%
  813  919  1732   106   29.530600   0.000039%   0.000059%
  821  928  1749   107   29.530589  -0.000000%   0.000020%
  822  929  1751   107   29.530554  -0.000119%  -0.000098%
  829  937  1766   108   29.530578  -0.000039%  -0.000018%
  836  945  1781   109   29.530601   0.000040%   0.000060%
  837  946  1783   109   29.530566  -0.000076%  -0.000056%
  859  971  1830   112   29.530601   0.000041%   0.000061%
  867  980  1847   113   29.530590   0.000004%   0.000024%
  868  981  1849   113   29.530557  -0.000108%  -0.000088%
  875  989  1864   114   29.530579  -0.000033%  -0.000012%
  882  997  1879   115   29.530601   0.000042%   0.000062%
  883  998  1881   115   29.530569  -0.000068%  -0.000048%

64 results obtained.