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 A132052 #5 Jan 05 2021 22:05:24 %S A132052 1,84,4662,220500,9740115,419625360,18048090060,785470565880, %T A132052 34872721208325,1587323312675100,74301594199682850, %U A132052 3583275362669702700,178220792065162821975,9146316814629741747000,484394828691800237211000 %N A132052 Seventh column of triangle A035342. %C A132052 a(n), n >= 7, enumerates unordered forests composed of seven plane increasing ternary trees with n vertices. See A001147 (number of increasing ternary trees) and a D. Callan comment there. For a picture of some ternary trees see a W. Lang link under A001764. %F A132052 E.g.f.: ((x*c(x/2)*(1-2*x)^(-1/2))^7)/7!, where c(x) = g.f. for Catalan numbers A000108, a(0) := 0. %F A132052 E.g.f.: (-1+(1-2*x)^(-1/2))^7/7!. %e A132052 a(8)=84=3*binomial(8,2) increasing ternary 7-forest with n=8 vertices: there are three 7-forests (six 1-vertex trees together with any of the three different 2-vertex trees) each with binomial(8,2)= 28 increasing labelings. %Y A132052 Cf. A132051 (sixth column). %K A132052 nonn,easy %O A132052 7,2 %A A132052 _Wolfdieter Lang_ Sep 14 2007