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A260822 Lexicographically smallest permutation of the natural numbers, such that a(n)+n is a composite number and a(n) != n. 2
3, 4, 1, 2, 7, 8, 5, 6, 11, 12, 9, 10, 14, 13, 17, 18, 15, 16, 20, 19, 23, 24, 21, 22, 26, 25, 28, 27, 31, 32, 29, 30, 35, 36, 33, 34, 38, 37, 41, 42, 39, 40, 44, 43, 46, 45, 48, 47, 50, 49, 53, 54, 51, 52, 56, 55, 58, 57, 60, 59, 62, 61, 65, 66, 63, 64, 68 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The permutation is self-inverse: a(a(n)) = n;

by definition there are no fixed points.

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)

import Data.List (delete)

a260822 n = a260822_list !! (n-1)

a260822_list = f 1 [1..] where

   f x zs = g zs where

     g (y:ys) = if y /= x && a010051' (x + y) == 0

                   then y : f (x + 1) (delete y zs) else g ys

CROSSREFS

Cf. A010051, A002808, A260933.

Sequence in context: A343613 A333454 A021971 * A256008 A171073 A021297

Adjacent sequences:  A260819 A260820 A260821 * A260823 A260824 A260825

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Aug 04 2015

STATUS

approved

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Last modified August 5 00:15 EDT 2021. Contains 346456 sequences. (Running on oeis4.)