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 A082039 #7 Oct 29 2024 19:04:24 %S A082039 1,1,1,1,3,1,1,7,7,1,1,13,21,13,1,1,21,43,43,21,1,1,31,73,91,73,31,1, %T A082039 1,43,111,157,157,111,43,1,1,57,157,241,273,241,157,57,1,1,73,211,343, %U A082039 421,421,343,211,73,1,1,91,273,463,601,651,601,463,273,91,1,1,111,343,601,813,931,931,813,601,343,111,1 %N A082039 Symmetric square array defined by T(n,k) = k^2*n^2 + k*n + 1, read by antidiagonals. %e A082039 Square array T(n,k) begins: %e A082039 1 1 1 1 1 1 ... %e A082039 1 3 7 13 21 31 ... %e A082039 1 7 21 43 73 111 ... %e A082039 1 13 43 91 157 241 ... %e A082039 1 21 73 157 273 421 ... %e A082039 ... %Y A082039 Rows include A054569, A002061, A082040, A082041. %Y A082039 Main diagonal is A059826. %Y A082039 Cf. A082038. %K A082039 easy,nonn,tabl %O A082039 0,5 %A A082039 _Paul Barry_, Apr 02 2003