The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A189418 Number of rhombi on an n X n grid (or geoboard). 6
 0, 1, 6, 22, 66, 151, 312, 564, 984, 1601, 2478, 3622, 5242, 7271, 9856, 13124, 17296, 22229, 28286, 35306, 43850, 53891, 65520, 78624, 94272, 111977, 131990, 154514, 180290, 208611, 240840, 276032, 315720, 359497, 407470, 460078, 519018, 582447, 651232, 725820, 808416 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS R. H. Hardin, Ray Chandler, Table of n, a(n) for n = 1..1000 (first 92 terms from R. H. Hardin) Nathaniel Johnston, C program for computing terms Eric Weisstein's World of Mathematics, Rhombus CROSSREFS Cf. A189413, A189414. Sequence in context: A099855 A347435 A003469 * A027992 A271389 A353703 Adjacent sequences: A189415 A189416 A189417 * A189419 A189420 A189421 KEYWORD nonn AUTHOR Martin Renner, Apr 21 2011 EXTENSIONS a(6)-a(28) from Nathaniel Johnston, Apr 23 2011 Terms beyond a(28) by R. H. Hardin, May 04 2011 STATUS approved

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

Last modified December 10 02:09 EST 2022. Contains 358712 sequences. (Running on oeis4.)