A055053 Numbers of the form 4^i*(8j+7) or 4^i*(5j+-2).

2, 3, 7, 8, 12, 13, 15, 17, 18, 22, 23, 27, 28, 31, 32, 33, 37, 38, 39, 42, 43, 47, 48, 52, 53, 55, 57, 58, 60, 62, 63, 67, 68, 71, 72, 73, 77, 78, 79, 82, 83, 87, 88, 92, 93, 95, 97, 98, 102, 103, 107, 108, 111, 112, 113, 117, 118, 119, 122, 123

Offset

1,1

Comments

The numbers not of the form x^2+5y^2+5z^2.

Links

Table of n, a(n) for n=1..60.

L. J. Mordell, A new Waring's problem with squares of linear forms, Quart. J. Math., 1 (1930), 276-288 (see p. 283).

Mathematica

Module[{upto=150}, Select[Union[Flatten[Table[4^i {8j+7, 5j+2, 5j-2}, {i, 0, 5}, {j, 0, 30}]]], #>0 && #<=upto&]] (* Harvey P. Dale, May 31 2023 *)

Crossrefs

Sequence in context: A273944 A214324 A102664 * A233998 A047221 A331078

Adjacent sequences: A055050 A055051 A055052 * A055054 A055055 A055056

Keyword

nonn

Author

N. J. A. Sloane, Jun 02 2000

Status

approved