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 A078501 #8 Jul 02 2025 17:53:33
%S A078501 1,7,26,78,211,537,1312,3112,7217,16443,36934,82002,180319,393325,
%T A078501 852092,1835148,3932317,8388783,17825986,37748950,79692011,167772417,
%U A078501 352321816,738197808,1543504201,3221225827,6710886782,13958644122
%N A078501 a(n) = Sum_{k=1..n^2} A078446(k).
%F A078501 a(n) = 2*(n-2)*2^n + n*(n+1)/2 + 4
%F A078501 G.f.: x*(1-4*x^2+4*x^3)/((2*x-1)^2 * (1-x)^3) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]
%o A078501 (PARI) a(n)=2*(n-2)*2^n +n*(n+1)/2+4
%K A078501 nonn
%O A078501 1,2
%A A078501 _Benoit Cloitre_, Jan 04 2003
%E A078501 G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.