cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A202665 Number of -n..n arrays of 5 elements with first through fourth differences also in -n..n.

Original entry on oeis.org

19, 213, 1101, 3785, 10205, 23425, 47713, 89007, 154971, 255311, 401933, 609517, 895003, 1278825, 1784361, 2438483, 3271643, 4318837, 5618137, 7213161, 9151545, 11485961, 14273951, 17579509, 21470299, 26021835, 31314591, 37435583, 44478011
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2011

Keywords

Comments

Row 5 of A202664.

Examples

			Some solutions for n=8
.-1....8...-4...-2....7....6...-4...-8...-5....2....2....1....8...-3....8....5
.-6....4...-5....1....6....6...-3...-5....0...-1....5....0....8...-1....6....1
.-6....3...-3...-2....7....7...-2...-3...-1....1....8...-1....7...-2....4....0
.-6....4...-1...-4....7....8...-1....2...-1....2....5...-5....6...-6....3....0
.-8....0....5...-4....2....5....3....6....6....0...-3...-7....6...-6....3...-1
		

Crossrefs

Cf. A202664.

Formula

Empirical: a(n) = 2*a(n-3) +2*a(n-4) +a(n-5) -4*a(n-7) -3*a(n-8) -4*a(n-9) +2*a(n-11) +5*a(n-12) +5*a(n-13) +2*a(n-14) -4*a(n-16) -3*a(n-17) -4*a(n-18) +a(n-20) +2*a(n-21) +2*a(n-22) -a(n-25).