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A067017 Start with a(0)=1, a(1)=4, a(2)=3, a(3)=2; for n>=3, a(n+1) = mex_i (a(i)+a(n-i)), where mex means smallest nonnegative missing number. 6
1, 4, 3, 2, 0, 0, 0, 0, 0, 5, 1, 1, 1, 1, 1, 6, 2, 2, 0, 0, 0, 0, 0, 5, 1, 1, 1, 1, 1, 6, 2, 2, 0, 0, 0, 0, 0, 5, 1, 1, 1, 1, 1, 6, 2, 2, 0, 0, 0, 0, 0, 5, 1, 1, 1, 1, 1, 6, 2, 2, 0, 0, 0, 0, 0, 5, 1, 1, 1, 1, 1, 6, 2, 2, 0, 0, 0, 0, 0, 5, 1, 1, 1, 1, 1, 6, 2, 2, 0, 0, 0, 0, 0, 5, 1, 1, 1, 1, 1, 6, 2, 2, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, E27.

LINKS

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

PROG

(Haskell)

import Data.List ((\\))

a067017 n = a067017_list !! n

a067017_list =  [1, 4, 3, 2] ++ f [2, 3, 4, 1] where

  f xs = mexi : f (mexi : xs) where

    mexi = head $ [0..] \\ zipWith (+) xs (reverse xs)

-- Reinhard Zumkeller, May 05 2012

CROSSREFS

Cf. A067016, A067018.

Sequence in context: A154960 A143543 A176863 * A258692 A067018 A200233

Adjacent sequences:  A067014 A067015 A067016 * A067018 A067019 A067020

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Feb 17 2002

EXTENSIONS

More terms from John W. Layman, Feb 20 2002

STATUS

approved

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Last modified June 20 20:36 EDT 2021. Contains 345235 sequences. (Running on oeis4.)