A172497 Triangle T(n, k) = round( c(n)/(c(k)*c(n-k)) ) where c(n) = Product_{j=1..n} A029826(j+10), read by rows.
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 1, 1, 1, 2, 2, 4, 2, 2, 1, 1, 3, 6, 6, 6, 6, 3, 1, 1, 2, 6, 12, 6, 12, 6, 2, 1, 1, 4, 8, 24, 24, 24, 24, 8, 4, 1, 1, 3, 12, 24, 36, 72, 36, 24, 12, 3, 1, 1, 5, 15, 60, 60, 180, 180, 60, 60, 15, 5, 1, 1, 5, 25, 75, 150, 300, 450, 300, 150, 75, 25, 5, 1
Offset: 0
Examples
The triangle begins as: 1; 1, 1; 1, 1, 1; 1, 1, 1, 1; 1, 2, 2, 2, 1; 1, 1, 2, 2, 1, 1; 1, 2, 2, 4, 2, 2, 1; 1, 3, 6, 6, 6, 6, 3, 1; 1, 2, 6, 12, 6, 12, 6, 2, 1; 1, 4, 8, 24, 24, 24, 24, 8, 4, 1; 1, 3, 12, 24, 36, 72, 36, 24, 12, 3, 1;
Links
- G. C. Greubel, Rows n = 0..50 of the triangle, flattened
Crossrefs
Cf. A029826.
Programs
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Magma
R
:= PowerSeriesRing(Integers(), 100); b:= Coefficients(R!( 1/(1+x-x^3-x^4-x^5-x^6-x^7+x^9+x^10) )); c:= func< n | (&*[b[j]: j in [10..n+10]]) >; T:= func< n,k | Round(c(n)/(c(k)*c(n-k))) >; [T(n,k): k in [0..n], n in [1..12]]; // G. C. Greubel, Apr 20 2021 -
Mathematica
b:= Drop[CoefficientList[Series[1/(1+x-x^3-x^4-x^5-x^6-x^7+x^9+x^10), {x,0,100}], x], 10]; c[n_]:= Product[b[[j]], {j,n}]; T[n_, k_]:= Round[c[n]/(c[k]*c[n-k])]; Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Apr 20 2021 *)
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Sage
@CachedFunction def A029826_list(prec): P.
= PowerSeriesRing(ZZ, prec) return P( 1/(1+x-x^3-x^4-x^5-x^6-x^7+x^9+x^10) ).list() b=A029826_list(130) def c(n): return product(b[j] for j in (9..n+9)) def T(n,k): return round(c(n)/(c(k)*c(n-k))) flatten([[T(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Apr 20 2021
Formula
T(n, k) = round( c(n)/(c(k)*c(n-k)) ) where c(n) = Product_{j=1..n} A029826(j+10).
Extensions
Definition corrected and edited by G. C. Greubel, Apr 20 2021
Comments