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 A173043 #7 Feb 19 2021 18:34:28 %S A173043 1,1,1,1,5,1,1,10,10,1,1,19,261,19,1,1,36,32777,32777,36,1,1,69, %T A173043 16777230,68719476755,16777230,69,1,1,134,34359738388, %U A173043 1180591620717411303458,1180591620717411303458,34359738388,134,1 %N A173043 Triangle T(n, k, q) = binomial(n, k) - 1 + q^(n*binomial(n-2, k-1)) with T(n, 0, q) = T(n, n, q) = 1 and q = 2, read by rows. %H A173043 G. C. Greubel, <a href="/A173043/b173043.txt">Rows n = 0..12 of the triangle, flattened</a> %F A173043 T(n, k, q) = binomial(n, k) - 1 + q^(n*binomial(n-2, k-1)) with T(n, 0, q) = T(n, n, q) = 1 and q = 2. %F A173043 Sum_{k=0..n} T(n, k, 2) = A000295(n) + Sum_{k=0..n} 2^(n*binomial(n-2, k-1)). - _G. C. Greubel_, Feb 19 2021 %e A173043 Triangle begins as: %e A173043 1; %e A173043 1, 1; %e A173043 1, 5, 1; %e A173043 1, 10, 10, 1; %e A173043 1, 19, 261, 19, 1; %e A173043 1, 36, 32777, 32777, 36, 1; %e A173043 1, 69, 16777230, 68719476755, 16777230, 69, 1; %t A173043 T[n_, k_, q_]:= If[k==0 || k==n, 1, Binomial[n, k] - 1 + q^(n*Binomial[n-2, k-1])]; %t A173043 Table[t[n, k, 2], {n,0,12}, {k,0,n}]//Flatten (* modified by _G. C. Greubel_, Feb 19 2021 *) %o A173043 (Sage) %o A173043 def T(n,k,q): %o A173043 if (k==0 or k==n): return 1 %o A173043 else: return binomial(n,k) -1 +q^(n*binomial(n-2, k-1)) %o A173043 flatten([[T(n,k,2) for k in (0..n)] for n in (0..12)]) # _G. C. Greubel_, Feb 19 2021 %o A173043 (Magma) %o A173043 T:= func< n,k,q | k eq 0 or k eq n select 1 else Binomial(n,k) -1 +q^(n*Binomial(n-2, k-1)) >; %o A173043 [T(n,k,2): k in [0..n], n in [0..12]]; // _G. C. Greubel_, Feb 19 2021 %Y A173043 Cf. A132044 (q=0), A007318 (q=1), this sequence (q=2), A173045 (q=3). %Y A173043 Cf. A000295. %K A173043 nonn,tabl %O A173043 0,5 %A A173043 _Roger L. Bagula_, Feb 08 2010 %E A173043 Edited by _G. C. Greubel_, Feb 19 2021