This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A152719 #13 May 17 2021 04:33:12 %S A152719 1,1,1,1,2,1,1,2,2,1,1,2,5,2,1,1,2,5,5,2,1,1,2,5,12,5,2,1,1,2,5,12,12, %T A152719 5,2,1,1,2,5,12,29,12,5,2,1,1,2,5,12,29,29,12,5,2,1,1,2,5,12,29,70,29, %U A152719 12,5,2,1,1,2,5,12,29,70,70,29,12,5,2,1,1,2,5,12,29,70,169,70,29,12,5,2,1 %N A152719 Triangle read by rows: T(n,k) = A000129( 1 + min(k,n-k) ), n>=0, 0<=k<=n. %H A152719 G. C. Greubel, <a href="/A152719/b152719.txt">Rows n = 0..50 of the triangle, flattened</a> %F A152719 Sum_{k=0..n} T(n,k) = A238375(n). - _Philippe Deléham_, Feb 27 2014 %F A152719 T(2*n,n) = A000129(n+1). - _Philippe Deléham_, Feb 27 2014 %e A152719 Triangle begins as: %e A152719 1; %e A152719 1, 1; %e A152719 1, 2, 1; %e A152719 1, 2, 2, 1; %e A152719 1, 2, 5, 2, 1; %e A152719 1, 2, 5, 5, 2, 1; %e A152719 1, 2, 5, 12, 5, 2, 1; %e A152719 1, 2, 5, 12, 12, 5, 2, 1; %e A152719 1, 2, 5, 12, 29, 12, 5, 2, 1; %e A152719 1, 2, 5, 12, 29, 29, 12, 5, 2, 1; %e A152719 1, 2, 5, 12, 29, 70, 29, 12, 5, 2, 1; %t A152719 (* First program *) %t A152719 Pell[n_]:= Pell[n]= If[n<2, n, 2*Pell[n-1] + Pell[n-2]]; %t A152719 T[n_, k_]:= Pell[1 + Min[k, n-k]]; %t A152719 Table[T[n, k], {n,0,15}, {k,0,n}]//Flatten (* modified by _G. C. Greubel_, May 15 2021 *) %t A152719 (* Second program *) %t A152719 Table[Fibonacci[1 +Min[k, n-k], 2], {n,0,15}, {k,0,n}]//Flatten (* _G. C. Greubel_, May 15 2021 *) %o A152719 (Sage) %o A152719 def Pell(n): return n if (n<2) else 2*Pell(n-1) + Pell(n-2) %o A152719 def T(n,k): return Pell(1+min(k,n-k)) %o A152719 flatten([[T(n,k) for k in (0..n)] for n in (0..15)]) # _G. C. Greubel_, May 15 2021 %Y A152719 Cf. A000129, A238375 (row sums). %K A152719 nonn,tabl %O A152719 0,5 %A A152719 _Roger L. Bagula_, Dec 11 2008 %E A152719 Better name by _Philippe Deléham_, Feb 27 2014