cp's OEIS Frontend

A027062 a(n) = A027052(n, 2n-6).

%I A027062 #11 Nov 06 2019 04:27:34
%S A027062 1,1,3,11,37,123,401,1281,4023,12461,38175,115939,349701,1049063,
%T A027062 3133493,9327357,27687947,82009215,242473197,715889685,2111215763,
%U A027062 6220468653,18314669783,53892395679,158512474561,466071547105
%N A027062 a(n) = A027052(n, 2n-6).
%H A027062 G. C. Greubel, <a href="/A027062/b027062.txt">Table of n, a(n) for n = 3..750</a>
%p A027062 T:= proc(n, k) option remember;
%p A027062       if k<0 or k>2*n then 0
%p A027062     elif k=0 or k=2 or k=2*n then 1
%p A027062     elif k=1 then 0
%p A027062     else add(T(n-1, k-j), j=1..3)
%p A027062       fi
%p A027062     end:
%p A027062 seq( T(n,2*n-6), n=3..30); # _G. C. Greubel_, Nov 06 2019
%t A027062 T[n_, k_]:= T[n, k]= If[k<0 || k>2*n, 0, If[k==0 || k==2 || k==2*n, 1, If[k==1, 0, Sum[T[n-1, k-j], {j, 3}]]]]; Table[T[n,2*n-6], {n,3,30}] (* _G. C. Greubel_, Nov 06 2019 *)
%o A027062 (Sage)
%o A027062 @CachedFunction
%o A027062 def T(n, k):
%o A027062     if (k<0 or k>2*n): return 0
%o A027062     elif (k==0 or k==2 or k==2*n): return 1
%o A027062     elif (k==1): return 0
%o A027062     else: return sum(T(n-1, k-j) for j in (1..3))
%o A027062 [T(n,2*n-6) for n in (3..30)] # _G. C. Greubel_, Nov 06 2019
%K A027062 nonn
%O A027062 3,3
%A A027062 _Clark Kimberling_