A027032 a(n) = T(n,2n-8), T given by A027023.

1, 1, 5, 17, 57, 193, 649, 2161, 7113, 23137, 74417, 236913, 747401, 2339137, 7270189, 22460801, 69031105, 211206529, 643684485, 1955082321, 5920720729, 17884040961, 53898818389, 162120056257, 486791503521, 1459448379329

Offset

4,3

Links

G. C. Greubel, Table of n, a(n) for n = 4..750

Maple

T:= proc(n, k) option remember;
      if k<3 or k=2*n then 1
    else add(T(n-1, k-j), j=1..3)
      fi
    end:
seq(T(n, 2*n-8), n=4..30); # G. C. Greubel, Nov 05 2019

Mathematica

T[n_, k_]:= T[n, k]= If[n<0, 0, If[k<3 || k==2*n, 1, Sum[T[n-1, k-j], {j, 3}]]]; Table[T[n, 2*n-8], {n, 4, 30}] (* G. C. Greubel, Nov 05 2019 *)

Prog

(Sage)
@CachedFunction
def T(n, k):
    if (k<3 or k==2*n): return 1
    else: return sum(T(n-1, k-j) for j in (1..3))
[T(n, 2*n-8) for n in (4..30)] # G. C. Greubel, Nov 05 2019

Crossrefs

Sequence in context: A027030 A033538 A027093 * A027095 A027034 A027097

Adjacent sequences: A027029 A027030 A027031 * A027033 A027034 A027035

Keyword

nonn

Author

Clark Kimberling

Status

approved