id:A018811 - OEIS Search Results

Search: id:A018811

Displaying 1-1 of 1 results found.

page 1

Number of lines through exactly 4 points of an n X n grid of points.

+0
1

0, 0, 0, 0, 10, 4, 4, 20, 44, 36, 64, 124, 200, 236, 272, 308, 548, 692, 852, 1108, 1396, 1452, 1768, 2116, 2496, 2908, 3568, 4292, 5428, 5956, 6500, 7444, 8452, 8980, 10208, 11516, 13348, 14700, 16116, 17596, 20124, 22476, 24956, 28092, 31404, 33052, 36032 (list; graph; listen)

	OFFSET	`0,5`
	FORMULA	`1/2 (f(n, 6) - 2 f(n, 5) + f(n, 4)) where f(n, k) = Sum ((n - \|x\|)(n - \|y\|)); -n<x<n, -n<y<n, (x, y)=k.`
	CROSSREFS	`Sequence in context: A113315 A081986 A063566 this_sequence A100844 A076587 A040094` `Adjacent sequences: A018808 A018809 A018810 this_sequence A018812 A018813 A018814`
	KEYWORD	`nonn`
	AUTHOR	`David W. Wilson (davidwwilson(AT)comcast.net)`

page 1

Search completed in 0.002 seconds

Last modified December 2 15:58 EST 2008. Contains 150992 sequences.

AT&T Labs Research