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 A308871 #7 Jun 29 2019 17:06:47 %S A308871 0,0,0,0,0,0,1,1,2,4,7,11,19,26,40,57,81,109,153,198,264,342,442,556, %T A308871 710,875,1093,1338,1638,1975,2398,2855,3416,4040,4779,5595,6573,7627, %U A308871 8875,10244,11822,13549,15553,17707,20187,22883,25935,29239,32991,37010 %N A308871 Sum of the third largest parts in the partitions of n into 6 parts. %H A308871 <a href="/index/Par#part">Index entries for sequences related to partitions</a> %F A308871 a(n) = Sum_{m=1..floor(n/6)} Sum_{l=m..floor((n-m)/5)} Sum_{k=l..floor((n-l-m)/4)} Sum_{j=k..floor((n-k-l-m)/3)} Sum_{i=j..floor((n-j-k-l-m)/2)} j. %F A308871 a(n) = A308867(n) - A308868(n) - A308869(n) - A306670(n) - A308872(n) - A308873(n). %t A308871 Table[Sum[Sum[Sum[Sum[Sum[j, {i, j, Floor[(n - j - k - l - m)/2]}], {j, k, Floor[(n - k - l - m)/3]}], {k, l, Floor[(n - l - m)/4]}], {l, m, Floor[(n - m)/5]}], {m, Floor[n/6]}], {n, 0, 50}] %Y A308871 Cf. A238340, A308867, A308868, A308869, A306670, A308872, A308873. %K A308871 nonn %O A308871 0,9 %A A308871 _Wesley Ivan Hurt_, Jun 29 2019