OFFSET
1,3
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
K. Matthews, Finding the order of a (mod m)
FORMULA
MAPLE
f:= proc(n)
if igcd(n, 10)>1 then 0 else numtheory:-order(10, 9*n) fi
end proc:
map(f, [$1..100]); # Robert Israel, Feb 22 2019
MATHEMATICA
a[n_] := If[GCD[10, 9n] != 1, 0, MultiplicativeOrder[10, 9n]];
Array[a, 100] (* Jean-François Alcover, Jul 19 2020 *)
PROG
(PARI) a(n) = if (gcd(10, 9*n) != 1, 0, znorder(Mod(10, 9*n))); \\ Michel Marcus, Feb 23 2019
(GAP) List([1..100], n->OrderMod(10, 9*n)); # Muniru A Asiru, Feb 26 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Jun 30 2003
EXTENSIONS
More terms from John W. Layman, Oct 09 2003
STATUS
approved