|
|
A207041
|
|
Carmichael numbers that can be written as a product of two Carmichael numbers.
|
|
3
|
|
|
509033161, 1836304561, 5394826801, 20064165121, 25594002721, 47782272385, 59970791881, 75527369281, 84127131361, 96578912521, 116087568961, 278585544601, 387394248241, 416937760921, 584698468861, 1623222276481, 1690000282321, 1788750684721, 1945024664401
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
|
|
MATHEMATICA
|
(*M is the set of the first G (G<=10000) Carmichael numbers, as found in https://oeis.org/A002997/b002997.txt*) i=0; SPCM={}; While[i<G-1, i++; m=M[[i]]; j=i; While[j<G, j++; n=M[[j]]; If[GCD[m, n]==1, c=m n; If[c<=M[[1]] M[[G]], Fc=FactorInteger[c]; k=Length[Fc]; j2=0; While[j2<k, j2++; p=First[Fc[[j2]]]; If[Mod[c-1, p-1]!=0, j2=k+1]]; If[j2!=k+1, SPCM=Append[SPCM, c]]]]]]; SPCM=Union[SPCM]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|