OFFSET
1,2
LINKS
MATHEMATICA
b[n_] := b[n] = If[n==1, 1, If[EvenQ[n], 3b[n/2]-1, Floor[3b[(n+1)/2]/2]]];
a[n_] := Module[{k = 1}, While[n != b[k], k++]; k];
Array[a, 100] (* Jean-François Alcover, Sep 04 2021 *)
PROG
(Haskell)
import Data.List (elemIndex); import Data.Maybe (fromJust)
a259431 = (+ 1) . fromJust . (`elemIndex` a183209_list)
-- Reinhard Zumkeller, Jun 27 2015
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Alois P. Heinz, Jun 26 2015
STATUS
approved