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A213912 a(1) = 1; for n>1, a(n) = floor(sqrt(a(n-1))) if that number is not already in the sequence, otherwise a(n) = 3*a(n-1). 2
1, 3, 9, 27, 5, 2, 6, 18, 4, 12, 36, 108, 10, 30, 90, 270, 16, 48, 144, 432, 20, 60, 7, 21, 63, 189, 13, 39, 117, 351, 1053, 32, 96, 288, 864, 29, 87, 261, 783, 2349, 7047, 83, 249, 15, 45, 135, 11, 33, 99, 297, 17, 51, 153, 459, 1377, 37, 111, 333, 999, 31 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Permutation of natural numbers with inverse A213913;

LINKS

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

Index entries for sequences that are permutations of the natural numbers

PROG

(Haskell)

a213912 n = a213912_list !! (n-1)

a213912_list = 1 : f [1] where

   f xs@(x:_) = y : f (y : xs) where

     y = if z `notElem` xs then z else 3 * x where z = a000196 x

CROSSREFS

Cf. A114183.

Sequence in context: A114181 A036134 A317502 * A070360 A248131 A070346

Adjacent sequences:  A213909 A213910 A213911 * A213913 A213914 A213915

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 05 2013

STATUS

approved

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Last modified November 21 09:14 EST 2019. Contains 329362 sequences. (Running on oeis4.)