A111159 Numbers n such that A111075(n) is odd.

1, 3, 4, 6, 12, 16, 24, 25, 27, 48, 49, 54, 64, 75, 96, 100, 108, 121, 147, 150, 169, 192, 196, 216, 243, 256, 289, 294, 300, 361, 363, 384, 400, 432, 484, 486, 507, 529, 588, 600, 625, 675, 676, 726, 768, 784, 841, 864, 867, 961, 972, 1014, 1024

Offset

1,2

Links

Table of n, a(n) for n=1..53.

Formula

Conjecture: A111075(n) is odd whenever: (i) n = m^2 for all m>=1 such that 3 does not divide m, or (ii) n = 3*A028982(m) for all m>=1. Also, A028982 gives "Union of nonzero squares and twice squares."

It is not difficult to show that the conjecture is true. - Max Alekseyev, Oct 12 2005

Crossrefs

Sequence in context: A044843 A293593 A024373 * A210523 A109069 A329953

Adjacent sequences: A111156 A111157 A111158 * A111160 A111161 A111162

Keyword

nonn

Author

Paul D. Hanna, Oct 12 2005

Status

approved