looking at all messages above, here are the actual work to do ... with reservation (limited)
it includes all confirmed observation:
base 10 maybe screwed at the end (see post 49 or 50 from citrix and the possible bug in srsieve)
Code:
Base 6:
Sierpinski
1 to 243417
Reisel
1 to 213409
Base 7:
Totally horrible. Possible covering set with repeat every 24 n is [19,5,43,1201,13,181,193,73], also 5 other sets perming 73, 193 and 409.
Sierpinski and Riesel numbers are both lower than 162643669672445
Work is needed to find a low k value which is Riesel or Sierpinski.
Base 8:
Sierpinski
1
Riesel (done?)
Base 9:
Sierpinski (done ?)
Riesel
4 jasong
16
36
64
Note 16 and 64 are subsets of 4.
Base 10:
Sierpinski
804*10^n+1
1024*10^n+1
2157*10^n+1
2661*10^n+1
4069*10^n+1
5028*10^n+1
5512*10^n+1
5565*10^n+1
6172*10^n+1
7404*10^n+1
7666*10^n+1
7809*10^n+1
8194*10^n+1
8425*10^n+1
8667*10^n+1
8889*10^n+1
9021*10^n+1
9175*10^n+1
Riesel
1343*10^n-1
1803*10^n-1
1935*10^n-1
2276*10^n-1
2333*10^n-1
3356*10^n-1
4016*10^n-1
4421*10^n-1
4478*10^n-1
6588*10^n-1
6665*10^n-1
7019*10^n-1
8579*10^n-1
9701*10^n-1
9824*10^n-1
10176*10^n-1
Base 11:
Sierpinski
416 tnerual
958 tnerual
Riesel
62
682
862
904
1528
2410
2690
3110
3544
3788
4208
4564
Base 12:
Sierpinski
1 to 14599
Riesel
1 to 16328.
Base 13:
Sierpinski (done)
Riesel
288
Base 14: done
Base 15:
Horrible. A covering set is [241,113,211,17,1489,13,3877], and Sierpinski and Riesel values are therefore less than 7330957703181619. As bad as the base 3 problem.
Base 16:
Sierpinski number not known,
186 (to be removed see post #49 below by citrix)
2158 (tested up to n=4000 by citrix)
2857 (tested up to n=4000 by citrix)
2908 (tested up to n=4000 by citrix)
3061 (tested up to n=4000 by citrix)
4885 (tested up to n=4000 by citrix)
5886 (tested up to n=4000 by citrix)
6348 (tested up to n=4000 by citrix)
6663 (tested up to n=4000 by citrix)
6712 (tested up to n=4000 by citrix)
7212 (tested up to n=4000 by citrix)
7258 (tested up to n=4000 by citrix)
7615 (tested up to n=4000 by citrix)
7651 (tested up to n=4000 by citrix)
7773 (tested up to n=4000 by citrix)
8025 (tested up to n=4000 by citrix)
10001 to 66740
Riesel
1343*16^n-1
1803*16^n-1
1935*16^n-1
2333*16^n-1
3015*16^n-1
3332*16^n-1
4478*16^n-1
4500*16^n-1
4577*16^n-1
5499*16^n-1
5897*16^n-1
6588*16^n-1
6633*16^n-1
6665*16^n-1
7019*16^n-1
7602*16^n-1
8174*16^n-1
8579*16^n-1
10001 to 33965
Base 17:
Sierpinski
92 (LTD)
160 (LTD)
244 (LTD)
262 (LTD)
Riesel (done)
Base 18:
Sierpinski
18 xentar
324 xentar
122 xentar
381 xentar
Riesel (done)
Base 19:
?
Base 20:
?
Base 21:
Sierpinski
118 (checked to n=3500)
riesel (done)
Base 22:
Sierpinski
22
484
942
1611
1908
2991
4233
5061
5128
5659
6234
6462
Riesel
185
1013
1335
2853
3104
3426
3656
4001
4070
4118
4302
4440