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 A176340 #13 Sep 08 2022 08:45:52 %S A176340 1,1,1,1,-8,1,1,190,190,1,1,-14822,-14624,-14822,1,1,3557278,3542464, %T A176340 3542464,3557278,1,1,-2582583830,-2579026544,-2579041556,-2579026544, %U A176340 -2582583830,1,1,5640363084718,5637780500896,5637784057984,5637784057984,5637780500896,5640363084718,1 %N A176340 Triangle T(n,k) = 1 - A176338(k) - A176338(n-k) + A176338(n) read by rows. %C A176340 Row sums are: {1, 2, -6, 382, -44266, 14199486, -12902262302, 33831855287198, %C A176340 -258898313695820850, 5823405140242006622494, -386839522966544578870468774, ...}. %H A176340 G. C. Greubel, <a href="/A176340/b176340.txt">Rows n = 0..25 of triangle, flattened</a> %F A176340 T(n,k) = T(n,n-k). %e A176340 Triangle starts as: %e A176340 1; %e A176340 1, 1; %e A176340 1, -8, 1; %e A176340 1, 190, 190, 1; %e A176340 1, -14822, -14624, -14822, 1; %e A176340 1, 3557278, 3542464, 3542464, 3557278, 1; %t A176340 b[n_, q_]:= b[n, q]= If[n==0, 0, (1-q^n)*b[n-1, q] +1]; %t A176340 T[n_,k_,q_]:= 1 + b[n,q] -b[n-k,q] - b[k,q]; %t A176340 Table[T[n,k,3], {n,0,10}, {k,0,n}]//Flatten (* modified by _G. C. Greubel_, Dec 07 2019 *) %o A176340 (PARI) b(n,q) = if(n==0, 0, 1 + (1-q^n)*b(n-1,q) ); %o A176340 T(n,k,q) = 1 + b(n,q) - b(n-k,q) - b(k,q); %o A176340 for(n=0,10, for(k=0,n, print1(T(n,k,3), ", "))) \\ _G. C. Greubel_, Dec 07 2019 %o A176340 (Magma) %o A176340 function b(n,q) %o A176340 if n eq 0 then return 0; %o A176340 else return 1 - (q^n-1)*b(n-1,q); %o A176340 end if; return b; end function; %o A176340 function T(n,k,q) return 1 + b(n,q) - b(n-k,q) - b(k,q); end function; %o A176340 [ T(n,k,3) : k in [0..n], n in [0..10]]; // _G. C. Greubel_, Dec 07 2019 %o A176340 (Sage) %o A176340 @CachedFunction %o A176340 def b(n, q): %o A176340 if (n==0): return 0 %o A176340 else: return 1 - (q^n-1)*b(n-1,q) %o A176340 def T(n,k,q): return 1 + b(n,q) - b(n-k,q) - b(k,q) %o A176340 [[T(n,k,3) for k in (0..n)] for n in (0..10)] # _G. C. Greubel_, Dec 07 2019 %o A176340 (GAP) %o A176340 b:= function(n,q) %o A176340 if n=0 then return 0; %o A176340 else return 1 - (q^n-1)*b(n-1,q); %o A176340 fi; end; %o A176340 T:= function(n,k,q) return 1 + b(n,q) - b(n-k,q) - b(k,q); end; %o A176340 Flat(List([0..10], n-> List([0..n], k-> T(n,k,3) ))); # _G. C. Greubel_, Dec 07 2019 %Y A176340 Cf. A176337, A176338, A176339. %K A176340 sign,tabl %O A176340 0,5 %A A176340 _Roger L. Bagula_, Apr 15 2010 %E A176340 Edited by _G. C. Greubel_, Dec 07 2019