|
|
A204848
|
|
Algebraic cofactor of n-th repunit A002275(n).
|
|
3
|
|
|
1, 1, 1, 11, 1, 1221, 1, 1111, 333, 122221, 1, 11222211, 1, 12222221, 1233321, 11111111, 1, 111222222111, 1, 112222222211, 123333321, 1344444444431, 1, 1111222222221111, 11111, 12222222222221, 333333333, 1122222222222211, 1, 1011121222222221211101, 1, 1111111111111111, 1233333333321
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
LINKS
|
|
|
FORMULA
|
|
|
PROG
|
(PARI) lista(nn) = {vf = []; vfs = []; for (n=1, nn, if (n==1, print1(n, ", "), rn = (10^n-1)/9; f = factor(rn)[, 1]; vkeep = []; for (k = 1, #f~, if (!vecsearch(vfs, f[k]), vkeep = concat(vkeep, f[k])); ); print1(rn/prod(j=1, #vkeep, vkeep[j]), ", "); vf = concat(vf, vkeep); vfs = Set(vf); ); ); } \\ Michel Marcus, May 20 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|