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 A156582 #9 Sep 08 2022 08:45:41 %S A156582 1,1,1,1,1,2,1,1,3,6,1,1,4,27,24,1,1,5,64,729,120,1,1,6,125,4096, %T A156582 59049,720,1,1,7,216,15625,1048576,14348907,5040,1,1,8,343,46656, %U A156582 9765625,1073741824,10460353203,40320,1,1,9,512,117649,60466176,30517578125,4398046511104,22876792454961,362880 %N A156582 Square array T(n, k) = (k+2)^binomial(n, 2) with T(n, 0) = n!, read by antidiagonals. %H A156582 G. C. Greubel, <a href="/A156582/b156582.txt">Antidiagonal rows n = 0..50, flattened</a> %F A156582 T(n,k) = Product_{j=1..n} ( Sum_{i=0..j-1} binomial(j-1, i)*(k+1)^i ) with T(n, 0) = n! (square array). %F A156582 T(n, k) = (k+2)^binomial(n, 2) with T(n, 0) = n! (square array). - _G. C. Greubel_, Jun 28 2021 %e A156582 Square array begins as: %e A156582 1, 1, 1, 1, 1, 1 ...; %e A156582 1, 1, 1, 1, 1, 1 ...; %e A156582 2, 3, 4, 5, 6, 7 ...; %e A156582 6, 27, 64, 125, 216, 343 ...; %e A156582 24, 729, 4096, 15625, 46656, 117649 ...; %e A156582 120, 59049, 1048576, 9765625, 60466176, 282475249 ...; %e A156582 Antidiagonal triangle begins as: %e A156582 1; %e A156582 1, 1; %e A156582 1, 1, 2; %e A156582 1, 1, 3, 6; %e A156582 1, 1, 4, 27, 24; %e A156582 1, 1, 5, 64, 729, 120; %e A156582 1, 1, 6, 125, 4096, 59049, 720; %e A156582 1, 1, 7, 216, 15625, 1048576, 14348907, 5040; %e A156582 1, 1, 8, 343, 46656, 9765625, 1073741824, 10460353203, 40320; %t A156582 (* First program *) %t A156582 T[n_, k_]:= If[k==0, n!, Product[Sum[Binomial[j-1,i]*(k+1)^i, {i,0,j-1}], {j,n}]]; %t A156582 Table[T[k, n-k], {n,0,12}, {k,0,n}]//Flatten (* modified by _G. C. Greubel_, Jun 28 2021 *) %t A156582 (* Second program *) %t A156582 T[n_, k_]:= If[k==0, n!, (k+2)^Binomial[n, 2]]; %t A156582 Table[T[k, n-k], {n,0,12}, {k,0,n}]//Flatten (* _G. C. Greubel_, Jun 28 2021 *) %o A156582 (Magma) %o A156582 A156582:= func< n,k | k eq 0 select Factorial(n) else (k+2)^Binomial(n,2) >; %o A156582 [A156582(k,n-k): k in [0..n], n in [0..12]]; // _G. C. Greubel_, Jun 28 2021 %o A156582 (Sage) %o A156582 def A156582(n,k): return factorial(n) if (k==0) else (k+2)^binomial(n,2) %o A156582 flatten([[A156582(k,n-k) for k in (0..n)] for n in (0..12)]) # _G. C. Greubel_, Jun 28 2021 %Y A156582 Cf. A118180, A118185, A118190. %K A156582 nonn,tabl %O A156582 0,6 %A A156582 _Roger L. Bagula_, Feb 10 2009 %E A156582 Edited by _G. C. Greubel_, Jun 28 2021