Composites (original) (raw)

When and how Fermat numbers Fm were proven composite

(on the occasion of a remarkable discovery)

m Year Discoverer Method
5 1732 Euler Factorization
6 1855 Clausen Factorization
7 1905 Morehead Pépin test
8 1909 Morehead & Western Pépin test
9 1903 Western factor
10 1952 Robinson Pépin test
11 1899 Cunningham factors
12 1877 Pervushin / Lucas factor
13 1961 Paxson Pépin test
14 1961 Hurwitz & Selfridge Pépin test
15 1925 Kraitchik factor
16 1953 Selfridge factor
17 1979 Gostin factor
18 1903 Western factor
19 1962 Riesel factor
20 1987 Young & Buell Pépin test
21 1963 Wrathall factor
22 1993 Crandall & others Pépin test
23 1878 Pervushin factor
24 1999 Crandall & others Pépin test
25 1963 Wrathall factor
26 1963 Wrathall factor
27 1963 Wrathall factor
28 1997 Taura factor
29 1980 Gostin & McLaughlin factor
30 1963 Wrathall factor
31 2001 Kruppa & Forbes factor
32 1963 Wrathall factor
33 ---- u n k n o w n
34 ---- u n k n o w n
35 ---- u n k n o w n
36 1886 Seelhoff factor
37 1991 Gostin factor
38 1903 Cullen & Cunningham factor
39 1956 Robinson factor
40 2021 Morelli factor
41 ---- u n k n o w n
42 1963 Wrathall factor
43 2000 Samidoost factor
44 ---- u n k n o w n
45 ---- u n k n o w n
46 ---- u n k n o w n
47 ---- u n k n o w n
48 2001 Bodschwinna factor
49 ---- u n k n o w n
50 ---- u n k n o w n