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 A002942 M3370 N1357 #54 Dec 28 2023 07:07:53
%S A002942 1,4,9,61,52,63,94,46,18,1,121,441,961,691,522,652,982,423,163,4,144,
%T A002942 484,925,675,526,676,927,487,148,9,169,4201,9801,6511,5221,6921,9631,
%U A002942 4441,1251,61,1861,4671,9481,6391,5202,6112,9022,4032,1042,52,1062
%N A002942 a(n) = n^2 written backwards.
%C A002942 a(n) = A004086(A000290(n)). - _Reinhard Zumkeller_, Sep 18 2013
%D A002942 GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 103.
%D A002942 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002942 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A002942 T. D. Noe, <a href="/A002942/b002942.txt">Table of n, a(n) for n = 1..1000</a>
%H A002942 <a href="/index/Sq#sqrev">Index entry for sequences related to reversing digits of squares</a>
%e A002942 12*12 = 144, which written backwards is 441, so a(12) = 441.
%e A002942 10*10 = 100, so a(10) = 001 = 1.
%p A002942 a:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||(n^2)):
%p A002942 seq(a(n), n=1..60); # _Alois P. Heinz_, May 20 2022
%t A002942 Table[FromDigits[Reverse[IntegerDigits[n^2]]],{n,1,40}] (* _Geoffrey Critzer_, Dec 04 2011 *)
%o A002942 (Haskell)
%o A002942 a002942 = a004086 . a000290 -- _Reinhard Zumkeller_, Sep 18 2013
%o A002942 (Magma) [Seqint(Reverse(Intseq(n^2))): n in [1..60]]; // _Vincenzo Librandi_, Sep 21 2015
%Y A002942 Cf. A000290, A004086, A080334.
%K A002942 nonn,base,easy,look
%O A002942 1,2
%A A002942 _N. J. A. Sloane_
%E A002942 More terms from _Jeremy Gardiner_, Sep 08 2002