

A103391


'Even' fractal sequence for the natural numbers: Deleting every evenindex term results in the same sequence.


13



1, 2, 2, 3, 2, 4, 3, 5, 2, 6, 4, 7, 3, 8, 5, 9, 2, 10, 6, 11, 4, 12, 7, 13, 3, 14, 8, 15, 5, 16, 9, 17, 2, 18, 10, 19, 6, 20, 11, 21, 4, 22, 12, 23, 7, 24, 13, 25, 3, 26, 14, 27, 8, 28, 15, 29, 5, 30, 16, 31, 9, 32, 17, 33, 2, 34, 18, 35, 10, 36, 19, 37, 6, 38, 20, 39, 11, 40, 21, 41, 4, 42
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OFFSET

1,2


COMMENTS

A003602 is the 'odd' fractal sequence for the natural numbers.


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000


FORMULA

For n>2, a(n) = A003602(n2)+1.  Benoit Cloitre, May 26 2007
a((2*n3)*2^p+1) = n, p >= 0 and n >= 2, with a(1) = 1.  Johannes W. Meijer, Jan 28 2013


MAPLE

nmax := 82: for p from 0 to ceil(simplify(log[2](nmax))) do for n from 2 to ceil(nmax/(p+2))+1 do a((2*n3)*2^p+1) := n od: od: a(1) := 1: seq(a(n), n=1..nmax); # Johannes W. Meijer, Jan 28 2013


PROG

(Haskell)
 import Data.List (transpose)
a103391 n = a103391_list !! (n1)
a103391_list = 1 : ks where
ks = concat $ transpose [[2..], ks]
 Reinhard Zumkeller, May 23 2013


CROSSREFS

Cf. A003602, A220466.
Sequence in context: A205378 A323889 A286378 * A178804 A322355 A242112
Adjacent sequences: A103388 A103389 A103390 * A103392 A103393 A103394


KEYWORD

easy,nonn


AUTHOR

Eric Rowland, Mar 20 2005


STATUS

approved



