A027034 a(n) = T(n,2n-10), T given by A027023.

1, 1, 5, 17, 57, 193, 653, 2205, 7417, 24805, 82373, 271437, 887377, 2878509, 9268429, 29636981, 94163769, 297435285, 934521973, 2922073641, 9096981049, 28209178729, 87163760797, 268462020889, 824451264113, 2525238433145

Offset

5,3

Links

G. C. Greubel, Table of n, a(n) for n = 5..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-10), n=5..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-10], {n, 5, 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-10) for n in (5..30)] # G. C. Greubel, Nov 05 2019

Crossrefs

Sequence in context: A027093 A027032 A027095 * A027097 A098184 A289590

Adjacent sequences: A027031 A027032 A027033 * A027035 A027036 A027037

Keyword

nonn

Author

Clark Kimberling

Status

approved