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 A038397 #29 Feb 16 2024 10:21:49
%S A038397 1,41,941,16941,2516941,362516941,49362516941,6449362516941,
%T A038397 816449362516941,100816449362516941,121100816449362516941,
%U A038397 144121100816449362516941,169144121100816449362516941,196169144121100816449362516941,225196169144121100816449362516941
%N A038397 Concatenate first n squares in reverse order.
%D A038397 Mihaly Bencze [Beneze], L. Tutescu, Some Notions and Questions in Number Theory, Sequence 5.
%H A038397 Reinhard Zumkeller, <a href="/A038397/b038397.txt">Table of n, a(n) for n = 1..225</a>
%p A038397 a:= proc(n) a(n):= `if`(n=1, 1, parse(cat(n^2, a(n-1)))) end:
%p A038397 seq(a(n), n=1..20); # _Alois P. Heinz_, Jan 13 2021
%t A038397 Join[{s = 1}, Table[s = FromDigits[Flatten[IntegerDigits[{n^2, s}]]], {n, 2, 12}]] (* _Jayanta Basu_, Jul 14 2013 *)
%o A038397 (Haskell)
%o A038397 a038397 n = a038397_list !! (n-1)
%o A038397 a038397_list = f "" $ tail a000290_list where
%o A038397 f xs (q:qs) = (read ys :: Integer) : f ys qs
%o A038397 where ys = show q ++ xs
%o A038397 -- _Reinhard Zumkeller_, Mar 01 2014
%Y A038397 Cf. A000290, A019521.
%K A038397 nonn,base
%O A038397 1,2
%A A038397 M. I. Petrescu (mipetrescu(AT)yahoo.com)