login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A020691 Numbers of form 7 x^2 + 9 y^2. 0
0, 7, 9, 16, 28, 36, 37, 43, 63, 64, 72, 81, 88, 99, 109, 112, 121, 144, 148, 151, 172, 175, 184, 193, 207, 211, 225, 232, 252, 253, 256, 261, 288, 319, 324, 331, 333, 337, 343, 352, 379, 387, 396, 400, 424, 436, 441, 448, 457, 469, 477, 484, 487, 499, 504, 529, 553, 567 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..58.

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

MATHEMATICA

Take[Union[7#[[1]]+9#[[2]]&/@Tuples[Range[0, 20]^2, 2]], 60] (* Harvey P. Dale, Aug 22 2014 *)

CROSSREFS

Sequence in context: A213220 A087680 A249333 * A145830 A195563 A250292

Adjacent sequences:  A020688 A020689 A020690 * A020692 A020693 A020694

KEYWORD

easy,nonn

AUTHOR

David W. Wilson

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 14:15 EDT 2019. Contains 322386 sequences. (Running on oeis4.)