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A026786 a(n) = T(n, floor(n/2)), T given by A026780. 11
1, 1, 3, 5, 12, 24, 53, 117, 246, 580, 1178, 2916, 5768, 14834, 28731, 76221, 145108, 395048, 741392, 2063104, 3825418, 10847078, 19907156, 57373672, 104370554, 305110106, 550816506, 1630489090, 2924018194, 8751851866 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

MAPLE

T:= proc(n, k) option remember;

    if n<0 then 0;

    elif k=0 or k =n then 1;

    elif k <= n/2 then

        procname(n-1, k-1)+procname(n-2, k-1)+procname(n-1, k) ;

    else

        procname(n-1, k-1)+procname(n-1, k) ;

    fi ;

end proc:

seq(T(n, floor(n/2)), n=0..30); # G. C. Greubel, Nov 02 2019

MATHEMATICA

T[n_, k_]:= T[n, k]= If[n<0, 0, If[k==0 || k==n, 1, If[k<=n/2, T[n-1, k-1] + T[n-2, k-1] + T[n-1, k], T[n-1, k-1] + T[n-1, k] ]]];

Table[T[n, Floor[n/2]], {n, 0, 30}] (* G. C. Greubel, Nov 02 2019 *)

PROG

(Sage)

@CachedFunction

def T(n, k):

    if (n<0): return 0

    elif (k==0 or k==n): return 1

    elif (k<=n/2): return T(n-1, k-1) + T(n-2, k-1) + T(n-1, k)

    else: return T(n-1, k-1) + T(n-1, k)

[T(n, floor(n/2)) for n in (0..30)] # G. C. Greubel, Nov 02 2019

CROSSREFS

Cf. A026780, A026781, A026782, A026783, A026784, A026785, A026787, A026788, A026789, A026790.

Sequence in context: A224747 A036657 A047761 * A027246 A090345 A185087

Adjacent sequences:  A026783 A026784 A026785 * A026787 A026788 A026789

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified September 28 17:43 EDT 2020. Contains 337393 sequences. (Running on oeis4.)