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 A007819 #15 Sep 08 2022 08:44:35
%S A007819 1,10,129,2516,68405,2391495,102022809,5130659560,296881218693,
%T A007819 19415908147835,1415538531617771,113796709835547766,
%U A007819 9998149029974754103,952980844872975079231,97930011125976327934825
%N A007819 a(n) = Sum_{j=1..n} binomial(n^2, j).
%H A007819 Harvey P. Dale, <a href="/A007819/b007819.txt">Table of n, a(n) for n = 1..338</a>
%F A007819 a(n) = A066382(n) - 1. - _Peter Luschny_, Mar 06 2020
%p A007819 seq( add(binomial(n^2,j), j=1..n), n=1..20); # _G. C. Greubel_, Mar 06 2020
%t A007819 Table[Sum[Binomial[n^2,i],{i,n}],{n,20}] (* _Harvey P. Dale_, Nov 03 2013 *)
%o A007819 (PARI) vector(20, n, sum(j=1,n, binomial(n^2,j))) \\ _G. C. Greubel_, Mar 06 2020
%o A007819 (Magma) [ &+[Binomial(n^2,j): j in [1..n]]: n in [1..20]]; // _G. C. Greubel_, Mar 06 2020
%o A007819 (Sage) [sum(binomial(n^2,j) for j in (1..n)) for n in (1..20)] # _G. C. Greubel_, Mar 06 2020
%Y A007819 Cf. A066382.
%K A007819 nonn,easy
%O A007819 1,2
%A A007819 Joseph Lavinus Ganley (jwl8k(AT)server.cs.Virginia.EDU)