OFFSET
1,2
COMMENTS
The value 3 cannot appear in this sequence.
The value 1619 appears 1654 times among the first 10000 terms; this is visible as a dashed horizontal line in the corresponding scatterplot.
The most frequent values among the first 10000000 terms are:
Value Number of occurrences among the first 10000000 terms
------- ---------------------------------------------------
283763 16934
2017817 15701
1619 15274
55667 14706
2717873 9913
LINKS
MATHEMATICA
Table[Max[FactorInteger[#][[-1, 1]]&/@NestWhileList[If[EvenQ[#], #/2, 3#+1]&, n, #>1&]], {n, 70}] (* Harvey P. Dale, Jun 22 2020 *)
PROG
(PARI) a(n) = my (g=1); while (n>1, my (f=factor(n)); g=max(g, f[#f~, 1]); n=if (n%2, 3*n+1, n/2)); return (g)
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Feb 22 2018
STATUS
approved