A189418 Number of rhombi on an n X n grid (or geoboard).
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
Offset: 1
Keywords
Links
- 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
Extensions
a(6)-a(28) from Nathaniel Johnston, Apr 23 2011
Terms beyond a(28) by R. H. Hardin, May 04 2011