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 A049797 #14 Sep 08 2022 08:44:58
%S A049797 0,0,0,2,0,4,4,4,6,14,4,14,20,16,16,30,22,38,32,30,44,64,38,50,68,68,
%T A049797 66,92,66,94,94,96,122,130,90,124,154,158,136,174,148,188,194,172,210,
%U A049797 254,196,228,240,248,258,308,282,302,284
%N A049797 a(n) = Sum_{k = 2..n} T(n,k), array T as in A049800.
%H A049797 G. C. Greubel, <a href="/A049797/b049797.txt">Table of n, a(n) for n = 1..1000</a>
%p A049797 seq(add((n+1) mod floor((k+1)/2), k = 3..n), n = 1..60);
%t A049797 Table[Sum[Mod[n+1, Floor[(k+1)/2]], {k,3,n}], {n,60}] (* _G. C. Greubel_, Dec 09 2019 *)
%o A049797 (PARI) vector(60, n, sum(k=3,n, (n+1)%((k+1)\2)) ) \\ _G. C. Greubel_, Dec 09 2019
%o A049797 (Magma) [0,0] cat [ (&+[(n+1) mod Floor((k+1)/2): k in [3..n]]): n in [3..60]]; // _G. C. Greubel_, Dec 09 2019
%o A049797 (Sage) [sum( (n+1)%floor((k+1)/2) for k in (3..n)) for n in (1..60)] # _G. C. Greubel_, Dec 09 2019
%o A049797 (GAP) List([1..60], n-> Sum([3..n], k-> (n+1) mod Int((k+1)/2)) ); # _G. C. Greubel_, Dec 09 2019
%Y A049797 Cf. A049800.
%K A049797 nonn
%O A049797 1,4
%A A049797 _Clark Kimberling_