Engler — Figurate Numbers. 



49 



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



^ n (?i + l) {n + 2) (n + 'S) , (n-1) n (/i + l) (?i-f 2) 



d 



For rf=l, 



For ^=0, 



(U) 



Tahle 16. 

 which is identical with Table 6. 



Table 17. 

 which is identical with Table 6 and Table 16. 



