cp's OEIS Frontend

A026547 a(n) = T(n, floor(n/2)), T given by A026536.

%I A026547 #8 Apr 12 2022 01:35:27
%S A026547 1,1,1,1,5,6,16,19,65,79,251,306,1016,1247,4117,5069,16913,20889,
%T A026547 69865,86479,290455,360205,1212905,1506462,5085224,6324176,21389824,
%U A026547 26630423,90226449,112439094,381519416,475838291,1616684241,2017827545
%N A026547 a(n) = T(n, floor(n/2)), T given by A026536.
%H A026547 G. C. Greubel, <a href="/A026547/b026547.txt">Table of n, a(n) for n = 0..340</a>
%F A026547 a(n) = A026536(n, floor(n/2)).
%t A026547 T[n_, k_]:= T[n, k]= If[k==0 || k==2*n, 1, If[k==1 || k==2*n-1, Floor[n/2], If[EvenQ[n], T[n-1, k-2] +T[n-1, k-1] +T[n-1, k], T[n-1, k-2] +T[n-1, k]] ]];
%t A026547 Table[T[n, Floor[n/2]], {n,0,40}] (* _G. C. Greubel_, Apr 11 2022 *)
%o A026547 (SageMath)
%o A026547 @CachedFunction
%o A026547 def T(n, k): # A026536
%o A026547     if k < 0 or n < 0: return 0
%o A026547     elif k == 0 or k == 2*n: return 1
%o A026547     elif k == 1 or k == 2*n-1: return n//2
%o A026547     elif n % 2 == 1: return T(n-1, k-2) + T(n-1, k)
%o A026547     return T(n-1, k-2) + T(n-1, k-1) + T(n-1, k)
%o A026547 def A026547(n): return T(n, n//2)
%o A026547 [A026547(n) for n in (0..40)] # _G. C. Greubel_, Apr 11 2022
%Y A026547 Cf. A026536.
%K A026547 nonn
%O A026547 0,5
%A A026547 _Clark Kimberling_