A201086 Number of -6..6 arrays of n elements with first and second differences also in -6..6.

13, 127, 967, 7581, 59533, 468159, 3681179, 28943479, 227567727, 1789258703, 14068129953, 110611309721, 869686276975, 6837946387417, 53763653212357, 422719081839837, 3323647323173331, 26132322856122051, 205466534630289505

Offset

1,1

Comments

Column 6 of A201088.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 8*a(n-1) -14*a(n-3) +55*a(n-4) -58*a(n-5) -275*a(n-6) -13*a(n-7) +383*a(n-8) +435*a(n-9) +307*a(n-10) -386*a(n-11) -1187*a(n-12) -515*a(n-13) +895*a(n-14) +1171*a(n-15) +258*a(n-16) -717*a(n-17) -1121*a(n-18) -436*a(n-19) +947*a(n-20) +1146*a(n-21) -68*a(n-22) -827*a(n-23) -391*a(n-24) +230*a(n-25) +497*a(n-26) +139*a(n-27) -493*a(n-28) -458*a(n-29) +242*a(n-30) +498*a(n-31) +55*a(n-32) -279*a(n-33) -136*a(n-34) +58*a(n-35) +70*a(n-36) +5*a(n-37) -17*a(n-38) -2*a(n-39) +6*a(n-40) +a(n-41) -2*a(n-42) -2*a(n-43) for n>44.

Example

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

Crossrefs

Cf. A201088.

Sequence in context: A179550 A202662 A202122 * A139786 A016169 A125401

Adjacent sequences: A201083 A201084 A201085 * A201087 A201088 A201089

Keyword

nonn

Author

R. H. Hardin, Nov 26 2011

Status

approved