|
Search: id:A087272
|
|
|
| A087272 |
|
a(n) is the largest prime number in 3x+1 trajectory initiated at n;. |
|
+0
4
|
|
| 2, 5, 2, 5, 5, 17, 2, 17, 5, 17, 5, 13, 17, 53, 2, 17, 17, 29, 5, 2, 17, 53, 5, 29, 13, 1619, 17, 29, 53, 1619, 2, 29, 17, 53, 17, 37, 29, 101, 5, 1619, 2, 43, 17, 17, 53, 1619, 5, 37, 29, 29, 13, 53, 1619, 1619, 17, 43, 29, 101, 53, 61, 1619, 1619, 2, 37, 29, 101, 17, 13, 53
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
MATHEMATICA
|
c[x_] := (1-Mod[x, 2])*(x/2)+Mod[x, 2]*(3*x+1); c[1]=1; fpl[x_] := Delete[FixedPointList[c, x], -1] ofp[x_] := Part[fpl[x], Flatten[Position[PrimeQ[fpl[x]], True]]] Table[Max[ofp[w]], {w, 1, 256}]
|
|
CROSSREFS
|
Cf. A025586, A087232.
Sequence in context: A059855 A082881 A104289 this_sequence A107060 A016589 A089122
Adjacent sequences: A087269 A087270 A087271 this_sequence A087273 A087274 A087275
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Labos E. (labos(AT)ana.sote.hu), Sep 18 2003
|
|
|
Search completed in 0.002 seconds
|
