Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A071611
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A071611 Number of points (i,j,k) on the surface of a sphere around (0,0,0) with squared radius A071609(n). +0
3
6, 12, 24, 30, 48, 72, 96, 120, 144, 168, 192, 240, 264, 312, 336, 384, 408, 432, 480, 504, 528, 552, 576, 600, 672, 696, 720, 768, 816, 864, 936, 1008, 1032, 1056, 1104, 1200, 1248, 1296, 1344, 1440, 1512, 1584, 1680, 1704, 1752, 1848, 1920, 2016 (list; graph; listen)
OFFSET

1,1

COMMENT

a(n) = number of lattice point on sphere around (0,0,0) with r^2=A071609(n).

EXAMPLE

A sphere with radius 1 has 6 lattice points on its surface, so a(1)=6. A sphere with r=sqrt(2) passes through 12 lattice points of the shape (1,1,0), so a(2)=12. A sphere with r=sqrt(5) passes through 24 lattice points with shape (2,1,0), so a(3)=24. A sphere with r=sqrt(9) passes through 6 lattice points of shape (3,0,0) and through 24 lattice points of shape (2,2,1), so a(4)=6+24=30.

PROGRAM

(FORTRAN) See program given in A071609

CROSSREFS

Cf. A071342-A071344 A071609 A071610.

Sequence in context: A061822 A119840 A069171 this_sequence A119500 A110967 A000082

Adjacent sequences: A071608 A071609 A071610 this_sequence A071612 A071613 A071614

KEYWORD

nonn

AUTHOR

Hugo Pfoertner (hugo(AT)pfoertner.org), May 25 2002

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 10 00:48 EST 2009. Contains 170565 sequences.


AT&T Labs Research