[r-t] Grandsire Triples

[John Goldthorpe]

Robert Lee wrote:
>
> 2) a 20 lead block giving a regular (ditto) 18 part peal (using 
> permutations of 2-4 and 5-7)
Some 20 lead blocks are possible using permutations of 245 and 367.  
These are the ones that don't finish with rounds:

PBSBSBBSSPBSSPBBPPBB = 1264573
PBSSBBSBSPBSSPBBPPBB = 1264573
PSSBSSPBSSPSSBSSPPBB = 1264573
SSPBBPPBBPBSBSBBSSPB = 1435267
SSPBBPPBBPBSSBBSBSPB = 1435267
SSPSBBSBPPBBPBSBBSPB = 1435267
SSPSSBSSPPBBPSSBSSPB = 1435267

John