OFFSET
0,4
LINKS
M. Dairyko, S. Tyner, L. Pudwell and C. Wynn, Non-contiguous pattern avoidance in binary trees, 2012, arXiv:1203.0795 [math.CO], p. 18 (Class F).
Michael Dairyko, Lara Pudwell, Samantha Tyner, Casey Wynn, Non-contiguous pattern avoidance in binary trees. Electron. J. Combin. 19 (2012), no. 3, Paper 22, 21 pp. MR2967227.
Index entries for linear recurrences with constant coefficients, signature (3,-2,0,-1,1).
FORMULA
G.f.: x*(1-2*x+x^2+x^3+2*x^4)/((1-x)^2*(1-x-x^2-x^3)).
MATHEMATICA
Join[{0}, LinearRecurrence[{3, -2, 0, -1, 1}, {1, 1, 2, 5, 12}, 50]] (* Harvey P. Dale, Nov 12 2014 *)
CoefficientList[Series[x*(1-2*x+x^2+x^3+2*x^4)/((1-x)^2*(1-x-x^2-x^3)) , {x, 0, 50}], x] (* Stefano Spezia, Nov 29 2018 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Feb 01 2013
STATUS
approved