The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A020679 Numbers of form 3*x^2 + 7*y^2. 0
 0, 3, 7, 10, 12, 19, 27, 28, 31, 34, 40, 48, 55, 63, 66, 75, 76, 82, 90, 103, 108, 111, 112, 115, 124, 136, 138, 139, 147, 154, 160, 171, 175, 178, 187, 192, 199, 202, 210, 220, 223, 243, 250, 252, 255, 259, 264, 271, 279, 283, 300, 304, 306, 307, 322, 327, 328, 343, 346 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references) MATHEMATICA With[{upto=350}, Select[Union[3#[[1]]^2+7#[[2]]^2&/@Tuples[Range[ 0, Floor[(Sqrt[upto/3])]], 2]], #<+upto&]] (* Harvey P. Dale, Nov 17 2012 *) CROSSREFS Sequence in context: A310180 A310181 A310182 * A103541 A183178 A340604 Adjacent sequences:  A020676 A020677 A020678 * A020680 A020681 A020682 KEYWORD easy,nonn AUTHOR STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 30 03:54 EDT 2021. Contains 346347 sequences. (Running on oeis4.)