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 A342772 #12 Mar 23 2021 15:38:23 %S A342772 3,4,5,9,7,8,13,13,11,17,13,14,24,20,17,25,19,20,32,27,23,33,29,26,37, %T A342772 37,29,41,31,32,45,41,40,56,37,38,53,48,41,57,43,44,70,55,47,65,53,50, %U A342772 74,62,53,73,65,56,77,69,59,81,61,62,85,80,73,98,67,68,93,88,71,97 %N A342772 Row sums of triangle A177028. %H A342772 Michel Marcus, <a href="/A342772/b342772.txt">Table of n, a(n) for n = 3..10000</a> %F A342772 a(n) >= n. %F A342772 For m in A090466, a(m) > m. %F A342772 For m in A090467, a(m) = m. %e A342772 6 is a triangular and hexagonal number, so a(6) = 3 + 6 = 9. %o A342772 (PARI) a(n) = sum(k=3, n, if (ispolygonal(n, k), k)); %Y A342772 Cf. A090466, A090467, A177028. %K A342772 nonn %O A342772 3,1 %A A342772 _Michel Marcus_, Mar 21 2021