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 A179438 #6 May 14 2013 23:57:21 %S A179438 1,1,1,2,1,1,4,2,1,1,1,9,4,2,2,1,1,1,20,9,4,3 %N A179438 Number of rooted trees which can be associated with each unrestricted partition. %C A179438 Values can be calculated using simple multiplication when all the parts of a partition are unequal; however when two or more parts are equal avoid over counting by adjusting as illustrated in the example. %D A179438 N. L. Biggs, E. K. Lloyd and R. J. Wilson, Graph Theory 1736-1936, Clarendon Press, 1976, pages 40-43. %e A179438 Row six of the table begins: %e A179438 20 9 4 3 ... %e A179438 because the partitions begin: %e A179438 6 5+1 4+2 3+3 ... %e A179438 and A000081 begins 1,1,2,4,9,20,... %e A179438 the partition 3+3 has two equal terms so we write %e A179438 2*(2+1)/2! = 3. %e A179438 Likewise, 3+3+3 has three equal terms so the expression becomes %e A179438 2*(2+1)*(2+2)/3! %Y A179438 Cf. A000041 (shape sequence) A000081 (row sums) A144963 (a related triangle) %K A179438 nonn,tabf,uned %O A179438 1,4 %A A179438 _Alford Arnold_, Jul 14 2010