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 A334178 #23 May 04 2021 02:11:16 %S A334178 1,1,2,1,1,4,1,3,1,8,1,4,11,1,16,1,7,19,41,1,32,1,11,71,91,153,1,64,1, %T A334178 18,176,769,436,571,1,128,1,29,539,2911,8449,2089,2131,1,256,1,47, %U A334178 1471,17753,48301,93127,10009,7953,1,512,1,76,4271,79808,603126,801701,1027207,47956,29681,1,1024 %N A334178 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = 2^n * sqrt(Resultant(U_{2*n}(x/2), T_{k}(i*x/2))), where T_n(x) is a Chebyshev polynomial of the first kind, U_n(x) is a Chebyshev polynomial of the second kind and i = sqrt(-1). %F A334178 T(n,2*k) = A103997(n,k) for k > 0. %e A334178 Square array begins: %e A334178 1, 1, 1, 1, 1, 1, 1, ... %e A334178 2, 1, 3, 4, 7, 11, 18, ... %e A334178 4, 1, 11, 19, 71, 176, 539, ... %e A334178 8, 1, 41, 91, 769, 2911, 17753, ... %e A334178 16, 1, 153, 436, 8449, 48301, 603126, ... %e A334178 32, 1, 571, 2089, 93127, 801701, 20721019, ... %e A334178 64, 1, 2131, 10009, 1027207, 13307111, 714790675, ... %t A334178 T[n_, k_] := 2^n * Sqrt[Resultant[ChebyshevU[2*n, x/2], ChebyshevT[k, I*x/2], x]]; Table[T[k, n - k], {n, 0, 10}, {k, 0, n}] // Flatten (* _Amiram Eldar_, May 04 2021 *) %o A334178 (PARI) {T(n, k) = sqrtint(4^n*polresultant(polchebyshev(2*n, 2, x/2), polchebyshev(k, 1, I*x/2)))} %Y A334178 Rows 0..1 give A000012, A000032. %Y A334178 Columns 0..15 give A000079, A000012, A001835(n+1), A004253(n+1), A334135, A003729, A334179, A028478, A334180, A028480, A334181, A028482, A334182, A028484, A334183, A028486. %Y A334178 Cf. A103997. %K A334178 nonn,tabl %O A334178 0,3 %A A334178 _Seiichi Manyama_, Apr 17 2020