A182859 Numbers n such that A036459(n) is even.

1, 2, 4, 9, 12, 16, 18, 20, 24, 25, 28, 30, 32, 40, 42, 44, 45, 48, 49, 50, 52, 54, 56, 63, 64, 66, 68, 70, 75, 76, 78, 80, 81, 88, 92, 98, 99, 102, 104, 105, 110, 112, 114, 116, 117, 121, 124, 128, 130, 135, 136, 138, 144, 147, 148, 152, 153, 154, 162, 164, 165, 169, 170

Offset: 1

Author

Matthew Vandermast, Jan 05 2011

Keywords

• nonn

Comments

The sequence is also given by taking the smallest positive integer n such that A000005(n) is not already in the sequence. - Drake Thomas, May 05 2015

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Complement of A080218.

Programs

Maple

A036459:= proc(n) option remember;
  procname(numtheory:-tau(n))+1;
end proc:
A036459(1):= 0: A036459(2):= 0:
select(t -> A036459(t)::even, [$1..1000]); # Robert Israel, Aug 31 2015

Mathematica

Position[Table[Length[FixedPointList[DivisorSigma[0, #] &, n]] - 2, {n, 170}], Integer?EvenQ] // Flatten (* _Michael De Vlieger, Aug 31 2015, after Robert G. Wilson v at A036459 *)