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A185038
Positions at which A090895 (a(1) = 1 then a(n) = a(n-1)/2 if a(n-1) is even, a(n) = a(n-1) + n otherwise) reach the value of 1.
2
1, 8, 15, 64, 7069, 229826, 62906548, 104509874538, 209233407362, 474536678820, 2653613575299, 14802269029898
OFFSET
1,2
COMMENTS
It seems that this sequence is infinite.
EXAMPLE
Example: the sequence a(1)=1 then a(n)=a(n-1)/2 if a(n-1) is even, a(n) = a(n-1) + n otherwise goes 1, 3, 6, 3, 8, 4, 2, 1, 10, 5, 16, 8, 4, 2, 1, etc... which has ones at 1, 8, 15, 64, etc...
PROG
(Haskell)
import Data.List (elemIndices)
a185038 n = a185038_list !! (n-1)
a185038_list = map (+ 1) $ elemIndices 1 a090895_list
-- Reinhard Zumkeller, Mar 02 2012
CROSSREFS
Cf. A090895.
Sequence in context: A166704 A161342 A048732 * A193490 A015442 A253211
KEYWORD
more,hard,nonn
AUTHOR
Sergio Pimentel, Mar 01 2012
EXTENSIONS
a(8)-a(12) from Hiroaki Yamanouchi, Oct 04 2014
STATUS
approved