Engler — Figurate Numbers. 



49 



For the sum of (d) we have by (4) 



n (n + l) (71+2) (n+3) (n-1) n (n+1) (n + 2) 

 ^^ 1-2-3 1-2-3-4 ^ 



For d=3y these series become 

 12 2 2 2 

 113 5 7 

 1 3 8 15 

 1 1 2 10 25 



(II) 



Table 16. 



which is identical with Table 6. 



For ^=0, 



Table 17. 

 which is identical with Table 6 and Table 16. 



