A108084 Triangle, read by rows, where T(0,0) = 1, T(n,k) = 2^n*T(n-1,k) + T(n-1,k-1).
1, 2, 1, 8, 6, 1, 64, 56, 14, 1, 1024, 960, 280, 30, 1, 32768, 31744, 9920, 1240, 62, 1, 2097152, 2064384, 666624, 89280, 5208, 126, 1, 268435456, 266338304, 87392256, 12094464, 755904, 21336, 254, 1, 68719476736, 68451041280, 22638755840, 3183575040, 205605888, 6217920, 86360, 510, 1
Offset: 0
Examples
Triangle begins: 1; 2, 1; 8, 6, 1; 64, 56, 14, 1; 1024, 960, 280, 30, 1; 32768, 31744, 9920, 1240, 62, 1;
Links
- G. C. Greubel, Rows n = 0..50 of the triangle, flattened
Crossrefs
Programs
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Magma
function T(n,k,q) if k lt 0 or k gt n then return 0; elif k eq n then return 1; else return q^n*T(n-1,k,q) + T(n-1,k-1,q); end if; return T; end function; [T(n,k,2): k in [0..n], n in [0..10]]; // G. C. Greubel, Feb 20 2021
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Mathematica
T[n_, k_, q_]:= T[n,k,q]= If[k<0 || k>n, 0, If[k==n, 1, q^n*T[n-1,k,q] +T[n-1,k-1,q] ]]; Table[T[n,k,2], {n,0,10}, {k,0,n}]//Flatten (* G. C. Greubel, Feb 20 2021 *)
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Sage
def T(n, k, q): if (k<0 or k>n): return 0 elif (k==n): return 1 else: return q^n*T(n-1,k,q) + T(n-1,k-1,q) flatten([[T(n,k,2) for k in (0..n)] for n in (0..10)]) # G. C. Greubel, Feb 20 2021
Formula
Sum_{k=0..n} T(n, k) = A028362(n).
T(n,0) = 2^(n*(n+1)/2) = A006125(n+1). - Philippe Deléham, Nov 05 2006
T(n,k) = 2^binomial(n+1-k,2) * A022166(n,k) for 0 <= k <= n. - Werner Schulte, Mar 25 2019
Comments