A054012 Nonzero values of n read modulo (number of proper divisors of n).

2, 1, 1, 2, 2, 3, 1, 3, 1, 2, 3, 2, 2, 1, 2, 4, 2, 5, 4, 1, 3, 1, 2, 5, 1, 1, 5, 2, 3, 4, 2, 3, 3, 6, 2, 1, 2, 1, 8, 1, 1, 7, 1, 2, 4, 2, 1, 2, 1, 2, 8, 3, 4, 4, 4, 6, 1, 9, 5, 4, 2, 1, 1, 2, 1, 2, 1, 2, 4, 2, 5, 2, 4, 1, 2, 2, 3, 5, 8, 1, 2, 4, 1, 2, 2, 3, 7, 5, 3, 2, 2, 2, 6, 2, 4, 4, 1, 3, 1, 2, 1, 2, 6, 5, 1

Offset

1,1

Links

Table of n, a(n) for n=1..105.

Formula

a(n) = A054011(A054009(n)).

Maple

with(numtheory):
[seq(`if`(i mod (tau(i)-1) <> 0, i mod (tau(i)-1), print( )), i=2..220)];

Mathematica

Cases[Table[Mod[n, DivisorSigma[0, n]-1], {n, 2, 200}], Except[0]] (* Harvey P. Dale, Nov 12 2011 *)

Crossrefs

Cf. A000005, A032741, A054009, A054011.

Sequence in context: A325055 A325526 A057820 * A062083 A133114 A156265

Adjacent sequences: A054009 A054010 A054011 * A054013 A054014 A054015

Keyword

nonn

Author

Asher Auel, Jan 17 2000

Status

approved