OFFSET
0,2
COMMENTS
Define a triangle by T(n,n)=n+1 and T(n,0)=1 for n>=0, and T(r,c) = T(r,c-1) + T(r-1,c-1) + T(r-2,c-1). The sum of the terms in row n is a(n). - J. M. Bergot, Mar 01 2013
LINKS
Shalosh B. Ekhad and Doron Zeilberger, Automatic Solution of Richard Stanley's Amer. Math. Monthly Problem #11610 and ANY Problem of That Type, arXiv preprint arXiv:1112.6207, 2011. See subpages for rigorous derivations of g.f., recurrence, asymptotics for this sequence.
FORMULA
Conjecture: n*a(n) -4*n*a(n-1) +2*(n+3)*a(n-2) +4*(n-3)*a(n-3) +3*(-n+2)*a(n-4)=0. - R. J. Mathar, Jun 09 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 07 2012
STATUS
approved