858251         462486         123552        218251

Subtract each of the 2nd, 3rd and 4th terms from its preceding term and
write it between and below the two terms which were subtracted:

858251         462486         123552        218251
       -395767        -338934        94699


Do the same with the bottom row.

858251         462486         123552        218251
       -395767        -338934        94699
                56831         433633
                       376802  


Now repeat the 376802 and place it to the right of 376802

858251         462486         123552        218251
       -395767        -338934         94699
                56831         433633
                       376802        376802


Now we work backwards.  Add the 376802 to the 433633 getting 810435,
and write that to the right of the 433633

858251         462486         123552        218251
       -395767        -338934         94699
                56831         433633        810435
                       376802        376802


Add the 810435 to the 94699 getting 905134,
and write that to the right of the 94699

858251         462486         123552        218251
       -395767        -338934         94699        905134
                56831         433633        810435
                       376802        376802


Add the 905134 to the 218251 getting 1123385,
and write that to the right of the 218251, 

858251         462486         123552        218251        1123385
       -395767        -338934         94699        905134
                56831         433633        810435
                       376802        376802


So the next number in the series is 1123385

Edwin