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 A095222 #16 Feb 24 2021 09:02:43
%S A095222 0,19,22,52785,459136846,77032955851,17865523926168,1689623507805373,
%T A095222 118763391490664275,34129170492806856511,3616977859402101826424,
%U A095222 614427099275584124069065,34445463838393113230619233,2480185781714663029796564541499860
%N A095222 (Concatenation of T(n)+1..T(n+1)) mod (concatenation of T(n-1)+1..T(n)), where T(k) is the k-th triangular number, A000217(k).
%H A095222 Harvey P. Dale, <a href="/A095222/b095222.txt">Table of n, a(n) for n = 1..200</a>
%F A095222 a(n) = A053067(n+1) mod A053067(n). - _Hagen von Eitzen_, Jun 17 2009
%e A095222 a(3) = 78910 mod 456 = 22.
%e A095222 From _Jon E. Schoenfield_, Feb 23 2021: (Start)
%e A095222 .
%e A095222 concatenation of concatenation of
%e A095222 n T(n-1)+1..T(n) T(n)+1..T(n+1) a(n)
%e A095222 -- ---------------- ---------------- -----
%e A095222 1 1 23 0
%e A095222 2 23 456 19
%e A095222 3 456 78910 22
%e A095222 4 78910 1112131415 52785
%e A095222 (End)
%t A095222 ccat[a_,b_]:=FromDigits[Flatten[IntegerDigits/@Range[a,b]]]; modc[n_]: = Module[{w=(n(n-1))/2+1,x=(n(n+1))/2,y,z},y=x+1;z=2x-w+2; Mod[ccat[y,z], ccat[w,x]]]; Array[modc,20] (* _Harvey P. Dale_, Nov 27 2012 *)
%Y A095222 Cf. A000217, A053067.
%K A095222 base,nonn,less
%O A095222 1,2
%A A095222 _Amarnath Murthy_, Jun 10 2004
%E A095222 More terms from _Hagen von Eitzen_, Jun 17 2009
%E A095222 a(14) from _Harvey P. Dale_, Nov 27 2012