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 A321178 #67 Dec 03 2018 17:17:17 %S A321178 1,5,14,29,50,80,119,164,220,284,356,437,530,632,740,860,994,1138, %T A321178 1292,1457,1633,1819,2014,2219,2444,2675,2915,3169,3435,3709,3991, %U A321178 4291,4603,4927,5269,5620,5983,6359,6745,7144,7558,7984,8420,8866,9325,9790,10273 %N A321178 One-half the sum of the first 2n + 1 primes. %H A321178 Ray Chandler, <a href="/A321178/b321178.txt">Table of n, a(n) for n = 0..10000</a> %F A321178 a(n) = A109723(n)/2 = A007504(2n+1)/2. %Y A321178 Cf. A000040, A001223, A007504, A109723. %K A321178 nonn %O A321178 0,2 %A A321178 _Martin Michael Musatov_, Oct 29 2018