A200083 Number of 0..n arrays x(0..4) of 5 elements with zero 3rd differences.
2, 3, 8, 17, 26, 43, 64, 89, 122, 163, 208, 269, 334, 407, 496, 597, 702, 831, 968, 1117, 1286, 1471, 1664, 1889, 2122, 2371, 2648, 2945, 3250, 3595, 3952, 4329, 4738, 5171, 5616, 6109, 6614, 7143, 7712, 8309, 8918, 9583, 10264, 10973, 11726, 12511, 13312
Offset: 1
Keywords
Examples
Some solutions for n=6: ..2....1....2....3....0....4....0....5....0....6....6....3....6....0....4....3 ..3....3....4....4....4....4....0....6....3....2....3....3....3....1....3....5 ..3....4....5....4....6....4....0....6....4....0....2....3....1....2....2....6 ..2....4....5....3....6....4....0....5....3....0....3....3....0....3....1....6 ..0....3....4....1....4....4....0....3....0....2....6....3....0....4....0....5
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Crossrefs
Cf. A200082.
Formula
Empirical: a(n) = a(n-1) +a(n-3) -a(n-5) +a(n-6) -2*a(n-7) +a(n-8) -a(n-9) +a(n-11) +a(n-13) -a(n-14).
Empirical g.f.: x*(2 + x + 5*x^2 + 7*x^3 + 6*x^4 + 11*x^5 + 5*x^6 + 8*x^7 + 3*x^8 + x^9 + 2*x^10 + x^11 + x^12 - x^13) / ((1 - x)^4*(1 + x)^2*(1 - x + x^2)*(1 + x^2)*(1 + x + x^2)^2). - Colin Barker, May 17 2018
Comments