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 A323378 #18 Feb 16 2025 08:33:57 %S A323378 1,1,1,1,0,-1,1,-1,1,1,1,0,0,0,1,1,-1,-1,1,-1,-1,1,0,1,0,-1,0,-1,1,1, %T A323378 0,1,1,0,-1,1,1,0,-1,0,0,0,1,0,1,1,1,1,1,1,-1,-1,-1,1,1,1,0,0,0,-1,0, %U A323378 1,0,0,0,-1,1,-1,-1,1,-1,-1,1,-1,1,1,1,-1 %N A323378 Square array read by antidiagonals: T(n,k) = Kronecker symbol (-n/k), n >= 1, k >= 1. %C A323378 If A215200 is arranged into a square array A215200(n,k) = kronecker symbol(n/k) with n >= 0, k >= 1, then this sequence gives the other half of the array. %C A323378 Note that there is no such n such that the n-th row and the n-th column are the same. %H A323378 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/KroneckerSymbol.html">Kronecker Symbol</a>. %e A323378 Table begins %e A323378 1, 1, -1, 1, 1, -1, -1, 1, 1, 1, ... ((-1/k) = A034947) %e A323378 1, 0, 1, 0, -1, 0, -1, 0, 1, 0, ... ((-2/k) = A188510) %e A323378 1, -1, 0, 1, -1, 0, 1, -1, 0, 1, ... ((-3/k) = A102283) %e A323378 1, 0, -1, 0, 1, 0, -1, 0, 1, 0, ... ((-4/k) = A101455) %e A323378 1, -1, 1, 1, 0, -1, 1, -1, 1, 0, ... ((-5/k) = A226162) %e A323378 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, ... ((-6/k) = A109017) %e A323378 1, 1, -1, 1, -1, -1, 0, 1, 1, -1, ... ((-7/k) = A175629) %e A323378 1, 0, 1, 0, -1, 0, -1, 0, 1, 0, ... ((-8/k) = A188510) %e A323378 ... %o A323378 (PARI) T(n,k) = kronecker(-n, k) %Y A323378 Cf. A215200. %Y A323378 The first rows are listed in A034947, A188510, A102283, A101455, A226162, A109017, A175629, A188510, ... %K A323378 sign,tabl %O A323378 1,1 %A A323378 _Jianing Song_, Jan 12 2019