OFFSET
0,3
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Axel Bacher, Antonio Bernini, Luca Ferrari, Benjamin Gunby, Renzo Pinzani and Julian West, The Dyck pattern poset Discrete Math. 321 (2014), 12--23. MR3154009.
A. Bernini, L. Ferrari, R. Pinzani and J. West, The Dyck pattern poset, arXiv preprint arXiv:1303.3785, 2013
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = (14*n^3-84*n^2+124*n-84)/6 for n >= 6.
a(n) = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4) for n>6. - Colin Barker, Jul 10 2015
G.f.: (10*x^9-20*x^8+12*x^6+8*x^5+3*x^4-x^3+4*x^2-3*x+1) / (x-1)^4. - Colin Barker, Jul 10 2015
MATHEMATICA
LinearRecurrence[{4, -6, 4, -1}, {1, 1, 2, 5, 14, 41, 110, 245, 450, 739}, 50] (* Harvey P. Dale, Apr 10 2019 *)
PROG
(PARI) Vec((10*x^9-20*x^8+12*x^6+8*x^5+3*x^4-x^3+4*x^2-3*x+1)/(x-1)^4 + O(x^100)) \\ Colin Barker, Jul 10 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 27 2013
STATUS
approved