|
|
A084923
|
|
Consider the sequence b(1) = n, b(k) is the greatest prime factor of 3*b(k-1)+2. It is conjectured that this always becomes cyclic; a(n) = length of cycle (or 0 if no cycle is reached).
|
|
1
|
|
|
20, 1, 22, 21, 19, 20, 20, 20, 27, 2, 21, 25, 19, 22, 21, 20, 19, 21, 24, 26, 20, 20, 19, 28, 22, 20, 20, 20, 26, 20, 25, 21, 30, 20, 26, 22, 27, 27, 20, 29, 19, 2, 19, 28, 25, 21, 20, 21, 22, 25, 26, 20, 19, 20, 6, 20, 31, 22, 23, 20, 28, 21, 21, 23, 27, 20, 27, 22, 25, 20, 19, 22
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MATHEMATICA
|
f[n_] := Flatten[ Table[ # [[1]], {1} ] & /@ FactorInteger[ 3n + 2 ]][[ -1]]; Table[ Length[ NestWhileList[f, n, UnsameQ, All]] - 1, {n, 1, 72}]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|