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 A352015 #28 Mar 13 2022 19:06:28 %S A352015 1,6,3,15,18,2,28,45,5,7,45 %N A352015 Square array read by antidiagonals upwards: T(n,k) is the n-th number m such that the symmetric representation of sigma(m) has at least one subpart k, with n >= 1, k >= 1, m >= 1. %e A352015 The corner of the square array looks like this: %e A352015 1, 3, 2, 7, ... %e A352015 6, 18, 5, ... %e A352015 15, 45, ... %e A352015 28, ... %e A352015 ... %e A352015 For n = 3 and k = 2 we have that 45 is the third positive integer m whose symmetric representation of sigma(m) has at least one subpart 2, so T(3,2) = 45. %e A352015 For n = 5 and k = 1 we have that 45 is also the fifth positive integer m whose symmetric representation of sigma(m) has at least one subpart 1, so T(5,1) = 45. %Y A352015 Row 1 gives A351904. %Y A352015 Column 1 gives A000384. %Y A352015 Cf. A000203, A001227 (number of subparts), A196020, A235791, A236104, A237270, A237271, A237591, A237593, A279387 (definition of subparts), A280850, A280851 (subparts), A296508, A346875, A347529, A351819. %K A352015 nonn,tabl,more %O A352015 1,2 %A A352015 _Omar E. Pol_, Feb 28 2022