OFFSET
0,3
COMMENTS
a(n)=2*n if 2*n+1 is in A019340, otherwise a(n)<2*n. - Robert Israel, Apr 17 2019
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
MAPLE
f:= proc(n)
if n mod 3 = 1 then 0 else numtheory:-order(12, 2*n+1) fi
end proc:
0, seq(f(n), n=1..100); # Robert Israel, Apr 16 2019
MATHEMATICA
a[n_] := Module[{s}, s = SelectFirst[Range[EulerPhi[2n+1]], PowerMod[12, #, 2n+1] == 1&]; If[s === Missing["NotFound"], 0, s]];
a /@ Range[0, 100] (* Jean-François Alcover, Jun 04 2020 *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
N. J. A. Sloane and Amarnath Murthy, May 08 2002
STATUS
approved