A212785 Half the number of 0..n arrays of length 6 with second differences nonzero.

13, 162, 1238, 5104, 16594, 43727, 101743, 211461, 408430, 735896, 1261599, 2064329, 3259612, 4975687, 7395946, 10715635, 15205983, 21151890, 28937100, 38956477, 51737361, 67810309, 87873466, 112625630, 142969752, 179799242

Offset: 1

Author

R. H. Hardin May 27 2012

Keywords

• nonn

Comments

Row 4 of A212782

Examples

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

Links

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

Formula

Empirical: a(n) = a(n-2) +2*a(n-3) +2*a(n-4) -a(n-5) -2*a(n-6) -5*a(n-7) -3*a(n-8) +3*a(n-10) +6*a(n-11) +5*a(n-12) +3*a(n-13) -3*a(n-14) -5*a(n-15) -6*a(n-16) -3*a(n-17) +3*a(n-19) +5*a(n-20) +2*a(n-21) +a(n-22) -2*a(n-23) -2*a(n-24) -a(n-25) +a(n-27)