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 A348678 #9 Oct 29 2021 17:44:23 %S A348678 1,1,2,1,4,8,1,1,8,16,1,8,32,32,128,1,1,16,64,64,256,1,1,32,128,256, %T A348678 512,1024,1,1,1,64,256,512,1024,2048,1,16,128,256,2048,64,4096,4096, %U A348678 32768,1,1,32,256,512,4096,1024,8192,8192,65536 %N A348678 Triangle read by rows, T(n, k) = denominator([x^k] M(n, x)) where M(n,x) are the Mandelbrot-Larsen polynomials defined in A347928. %H A348678 Neil J. Calkin, Eunice Y. S. Chan, and Robert M. Corless, <a href="https://doi.org/10.5206/mt.v1i1.14037">Some Facts and Conjectures about Mandelbrot Polynomials</a>, Maple Trans., Vol. 1, No. 1, Article 14037 (July 2021). %H A348678 Michael Larsen, <a href="https://doi.org/10.1090/mcom/3564">Multiplicative series, modular forms, and Mandelbrot polynomials</a>, in: Mathematics of Computation 90.327 (Sept. 2020), pp. 345-377. Preprint: <a href="https://arxiv.org/abs/1908.09974">arXiv:1908.09974</a> [math.NT], 2019. %e A348678 Triangle starts: %e A348678 [0] 1 %e A348678 [1] 1, 2 %e A348678 [2] 1, 4, 8 %e A348678 [3] 1, 1, 8, 16 %e A348678 [4] 1, 8, 32, 32, 128 %e A348678 [5] 1, 1, 16, 64, 64, 256 %e A348678 [6] 1, 1, 32, 128, 256, 512, 1024 %e A348678 [7] 1, 1, 1, 64, 256, 512, 1024, 2048 %e A348678 [8] 1, 16, 128, 256, 2048, 64, 4096, 4096, 32768 %e A348678 [9] 1, 1, 32, 256, 512, 4096, 1024, 8192, 8192, 65536 %p A348678 # Polynomials M are defined in A347928. %p A348678 T := (n, k) -> denom(coeff(M(n, x), x, k)): %p A348678 for n from 0 to 9 do seq(T(n, k), k = 0..n) od; %Y A348678 T(n, n) = A046161(n). %Y A348678 Cf. A348679 (numerators), A347928, A088802 & A123854 (central elements). %K A348678 nonn,tabl,frac %O A348678 0,3 %A A348678 _Peter Luschny_, Oct 29 2021