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A026547
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a(n) = T(n, floor(n/2)), T given by A026536.
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2
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1, 1, 1, 1, 5, 6, 16, 19, 65, 79, 251, 306, 1016, 1247, 4117, 5069, 16913, 20889, 69865, 86479, 290455, 360205, 1212905, 1506462, 5085224, 6324176, 21389824, 26630423, 90226449, 112439094, 381519416, 475838291, 1616684241, 2017827545
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OFFSET
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0,5
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LINKS
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FORMULA
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MATHEMATICA
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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]] ]];
Table[T[n, Floor[n/2]], {n, 0, 40}] (* G. C. Greubel, Apr 11 2022 *)
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PROG
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(SageMath)
@CachedFunction
if k < 0 or n < 0: return 0
elif k == 0 or k == 2*n: return 1
elif k == 1 or k == 2*n-1: return n//2
elif n % 2 == 1: return T(n-1, k-2) + T(n-1, k)
return T(n-1, k-2) + T(n-1, k-1) + T(n-1, k)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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