A104026 Numbers that can be represented as k^2*j, 0 < j <= k but not if gcd(k, j) = 1.

32, 72, 108, 128, 200, 243, 288, 384, 392, 432, 486, 500, 512, 600, 675, 800, 864, 972, 1125, 1152, 1176, 1323, 1350, 1372, 1440, 1536, 1568, 1728, 1944, 1960, 2000, 2048, 2187, 2250, 2400, 2560, 2592, 2646, 2700, 2904, 3087, 3125, 3200, 3240, 3267, 3380

Offset

1,1

Comments

The complement of A104020 and A104021.

Links

Table of n, a(n) for n=1..46.

Example

32 is in the list because 32 = 4^2*2 but gcd(4,2) = 2.

Mathematica

A104020 = Take[Union[Flatten[Table[k^2 * j, {k, 70}, {j, k - 1}]]], 200]; A104021 = Take[Union[Flatten[Table[If[GCD[k, j] == 1, k^2 * j, {}], {k, 70}, {j, k - 1}]]], 150]; Complement[A104020, A104021]

Crossrefs

Cf. A104020, A104021.

Sequence in context: A106700 A250755 A216427 * A216417 A110230 A250756

Adjacent sequences: A104023 A104024 A104025 * A104027 A104028 A104029

Keyword

nonn

Author

Leroy Quet and Robert G. Wilson v, Feb 25 2005

Status

approved