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A103391 'Even' fractal sequence for the natural numbers: Deleting every even-index 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 (list; graph; refs; listen; history; text; internal format)
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(n-2)+1. - Benoit Cloitre, May 26 2007

a((2*n-3)*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*n-3)*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 !! (n-1)

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

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Last modified May 26 15:26 EDT 2019. Contains 323597 sequences. (Running on oeis4.)