A072007 a(0) = 0; for n>=1, a(n)=least nonnegative integer x such that |x-a(n-1)|>=n and x is not a(k) for any k<n.

0, 1, 3, 6, 2, 7, 13, 4, 12, 21, 5, 16, 28, 8, 22, 37, 9, 26, 44, 10, 30, 51, 11, 34, 58, 14, 40, 67, 15, 45, 75, 17, 49, 82, 18, 53, 89, 19, 57, 96, 20, 61, 103, 23, 68, 113, 24, 71, 119, 25, 76, 127, 27, 80, 134, 29, 85, 142, 31, 90, 150, 32

Offset

0,3

Comments

A permutation of the nonnegative integers.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Index entries for sequences that are permutations of the natural numbers

Prog

(Haskell)
import Data.List (delete)
a072007 n = a072007_list !! n
a072007_list = 0 : f 1 0 [1..] where
   f u v ws = g ws where
     g (x:xs) = if abs (x - v) < u
                   then g xs else x : f (u + 1) x (delete x ws)
-- Reinhard Zumkeller, Sep 04 2014

Crossrefs

Cf. A072008, A072009 (inverse).

Sequence in context: A169749 A169750 A249558 * A078783 A273465 A328503

Adjacent sequences: A072004 A072005 A072006 * A072008 A072009 A072010

Keyword

nonn

Author

Clark Kimberling, Jun 07 2002

Status

approved