A200547 Number of -2..2 arrays x(0..n+1) of n+2 elements with zero sum and nonzero second differences.

14, 76, 280, 1240, 4978, 21626, 91058, 393660, 1686980, 7309386, 31632968, 137600876, 599055566, 2615427970, 11433493630, 50075195034, 219589525108, 964264276780, 4238966033150, 18655002576606, 82175337524524, 362306822490256, 1598684706408864, 7059561038745824

Offset: 1

Author

R. H. Hardin, Nov 19 2011

Keywords

• nonn
• changed

Examples

			Some solutions for n=3:
..2....1....0....0...-2...-1....1....0....0....1...-2...-2...-1....0...-1....2
..0...-1....2...-2....1....1....0....2...-2....1....1...-1....2....0...-1...-1
.-1....1...-1....0...-1....0...-2...-2....2...-2....1....1....2...-1....1...-2
.-1...-1...-1....0....1....2...-1...-2...-1....2....0....0...-1....2....2....0
..0....0....0....2....1...-2....2....2....1...-2....0....2...-2...-1...-1....1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Crossrefs

Column 2 of A200553.