A236843 Triangle read by rows related to the Catalan transform of the Fibonacci numbers.
1, 1, 1, 2, 3, 1, 5, 9, 4, 1, 14, 28, 14, 6, 1, 42, 90, 48, 27, 7, 1, 132, 297, 165, 110, 35, 9, 1, 429, 1001, 572, 429, 154, 54, 10, 1, 1430, 3432, 2002, 1638, 637, 273, 65, 12, 1, 4862, 11934, 7072, 6188, 2548, 1260, 350, 90, 13, 1, 16796, 41990, 25194, 23256, 9996, 5508, 1700, 544, 104, 15, 1
Offset: 0
Examples
Triangle begins: 1; 1, 1; 2, 3, 1; 5, 9, 4, 1; 14, 28, 14, 6, 1; 42, 90, 48, 27, 7, 1; 132, 297, 165, 110, 35, 9, 1; Production matrix is: 1...1 1...2...1 0...1...1...1 0...1...1...2...1 0...0...0...1...1...1 0...0...0...1...1...2...1 0...0...0...0...0...1...1...1 0...0...0...0...0...1...1...2...1 0...0...0...0...0...0...0...1...1...1 0...0...0...0...0...0...0...1...1...2...1 0...0...0...0...0...0...0...0...0...1...1...1 ...
Links
- Andrew Howroyd, Table of n, a(n) for n = 0..1325 (rows 0..50)
Crossrefs
Programs
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Magma
F:=Factorial; A236843:= func< n,k | (1/4)*(6*k+5-(-1)^k)*F(2*n-Floor(k/2))/(F(n-k)*F(n+Floor((k+1)/2)+1)) >; [A236843(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jun 13 2022
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Mathematica
T[n_, k_]:= (1/4)*(6*k+5-(-1)^k)*(2*n-Floor[k/2])!/((n-k)!*(n+Floor[(k+1)/2]+1)!); Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Jun 13 2022 *)
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PARI
T(n, k) = (1/4)*(6*k + 5 - (-1)^k)*(2*n - (k\2))!/((n-k)!*(n + (k+1)\2 + 1)!) \\ Andrew Howroyd, Jan 04 2023
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SageMath
F=factorial def A236843(n,k): return (1/2)*(3*k+2+(k%2))*F(2*n-(k//2))/(F(n-k)*F(n+((k+1)//2)+1)) flatten([[A236843(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jun 13 2022
Formula
G.f. for the column k (with zeros omitted): C(x)^A032766(k+1) where C(x) is g.f. for Catalan numbers (A000108).
Sum_{k=0..n} T(n,k) = A109262(n+1).
Sum_{k=0..n} T(n+k,2k) = A026726(n).
Sum_{k=0..n} T(n+1+k,2k+1) = A026674(n+1).
T(n, k) = (1/4)*(6*k + 5 - (-1)^k)*(2*n - floor(k/2))!/((n-k)!*(n + floor((k+1)/2) + 1)!). - G. C. Greubel, Jun 13 2022
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