OFFSET
1,1
COMMENTS
A195470(a(n)) = 0 for n > 1. [Reinhard Zumkeller, Sep 21 2011]
REFERENCES
P. Moree, Appendix to V. Pless et al., Cyclic Self-Dual Z_4 Codes, Finite Fields Applic., vol. 3 pp. 48-69, 1997.
LINKS
T. D. Noe, Table of n, a(n) for n=1..1000
MATHEMATICA
divQ[n_] := For[k = 1, k <= n, k++, If[Divisible[2^k + 1, n], Return[True], If[k == n, Return[False]]]]; Select[Range[100], !divQ[#]& ] (* Jean-François Alcover, Jun 18 2012 *)
dndQ[n_]:=NoneTrue[2^Range[n]+1, Divisible[#, n]&]; Select[Range[100], dndQ] (* The program uses the NoneTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 10 2015 *)
PROG
(Haskell)
import Data.List (elemIndices)
a014661 n = a014661_list !! (n-1)
a014661_list = 2 : map (+ 1) (elemIndices 0 $ map a195470 [1..])
-- Reinhard Zumkeller, Sep 21 2011
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
EXTENSIONS
More terms from Henry Bottomley, May 19 2000
STATUS
approved