OFFSET
1,3
COMMENTS
a(n)=3077 corresponds to peak=9232.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
FORMULA
If n = 2^k (for integers k >= 0), a(n) = 1; otherwise a(n) = (A025586(n)-1)/3 =(A056959(n)-1)/3. - Paolo Xausa, Nov 13 2021
MAPLE
a:= proc(n) option remember; `if`(n=1, 1, max(
`if`(n::odd, n, 0), a(`if`(n::even, n/2, 3*n+1))))
end:
seq(a(n), n=1..88); # Alois P. Heinz, Nov 14 2021
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[OddQ[fpl[x]], True]]] Table[Max[ofp[w]], {w, 1, 256}]
(* Second program: *)
Array[Max@ Select[NestWhileList[If[EvenQ@ #, #/2, 3 # + 1] &, #, Unequal[#, 1, -1, -10, -34] &, 1, 10^4], OddQ] &, 69] (* Michael De Vlieger, May 15 2017, after Alonso del Arte at A025586 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Sep 18 2003
EXTENSIONS
Name simplified by Paolo Xausa, Nov 13 2021
STATUS
approved