A212779 Half the number of 0..5 arrays of length n+2 with second differences nonzero.
99, 546, 3010, 16594, 91482, 504337, 2780392, 15328203, 84503842, 465866699, 2568306672, 14158984054, 78057979457, 430330886291, 2372398990909, 13078951921338, 72103800421506, 397505707375713, 2191434937861300
Offset: 1
Keywords
Examples
Some solutions for n=5 ..3....0....4....3....1....1....3....1....4....1....4....3....4....0....3....3 ..0....1....0....4....0....0....4....4....0....3....0....4....1....3....4....0 ..2....5....3....1....1....1....4....3....5....4....5....1....2....3....4....0 ..3....0....3....5....3....5....1....3....5....1....3....5....0....5....5....2 ..3....1....5....2....3....5....3....1....0....1....3....5....4....4....5....0 ..5....5....2....5....5....0....2....5....2....0....5....2....5....2....0....5 ..2....1....0....2....5....2....5....2....0....2....0....0....4....2....3....0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A212782.
Formula
Empirical: a(n) = 3*a(n-1) +12*a(n-2) +12*a(n-3) -6*a(n-4) -18*a(n-5) -14*a(n-6) -11*a(n-7) -16*a(n-8) -11*a(n-9) -a(n-10).
Comments