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 A108457 #6 Sep 25 2018 15:29:36 %S A108457 1,1,3,8,23,60,161,404,1011,2440,5804,13462,30798,69082,152862,333094, %T A108457 716781,1522534,3198011,6642274,13657417,27805917,56097811,112183092, %U A108457 222496203,437787036,854936195,1657526884,3191478236,6104379829,11602006003,21916355387 %N A108457 Number of partitions of (n,n) into pairs (i,j) with i>0, j>=0. %C A108457 (a,b)+(x,y)=(a+x,b+y); unit is (0,0). %H A108457 Alois P. Heinz, <a href="/A108457/b108457.txt">Table of n, a(n) for n = 0..99</a> %F A108457 a(n) = A091438(2n,n). - _Alois P. Heinz_, Sep 24 2018 %e A108457 (2,2)=(1,2)+(1,0)=(1,1)+(1,1), so a(2)=3. %Y A108457 Main diagonal of A108456. %Y A108457 Cf. A000041, A091438, A108461. %K A108457 nonn %O A108457 0,3 %A A108457 _Christian G. Bower_, Jun 03 2005