A200444 Number of 0..n arrays x(0..7) of 8 elements with zero 3rd differences.
2, 3, 4, 5, 6, 9, 14, 19, 24, 33, 42, 53, 64, 77, 94, 115, 136, 159, 182, 209, 242, 279, 316, 355, 398, 445, 492, 549, 606, 673, 740, 811, 882, 957, 1042, 1137, 1232, 1331, 1430, 1541, 1652, 1779, 1906, 2037, 2176, 2323, 2470, 2623, 2786, 2961, 3140, 3327, 3514
Offset: 1
Keywords
Examples
Some solutions for n=10 ..0....4....6....9....9....0....8....2....2....6....7...10....1....7....8...10 ..4....7....6....9....8....3....7....3....5....3....4....6....2....7....5...10 ..7....9....6....9....7....5....6....4....7....1....2....3....3....7....3...10 ..9...10....6....9....6....6....5....5....8....0....1....1....4....7....2...10 .10...10....6....9....5....6....4....6....8....0....1....0....5....7....2...10 .10....9....6....9....4....5....3....7....7....1....2....0....6....7....3...10 ..9....7....6....9....3....3....2....8....5....3....4....1....7....7....5...10 ..7....4....6....9....2....0....1....9....2....6....7....3....8....7....8...10
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Formula
Empirical: a(n) = -a(n-3) +a(n-7) +2*a(n-10) +a(n-13) +a(n-15) -a(n-17) +a(n-18) -a(n-20) +a(n-21) -a(n-22) +a(n-24) -2*a(n-25) -2*a(n-28) -2*a(n-31) +a(n-32) -a(n-34) +a(n-35) -a(n-36) +a(n-38) -a(n-39) +a(n-41) +a(n-43) +2*a(n-46) +a(n-49) -a(n-53) -a(n-56).
Comments