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 A055436 #21 Nov 18 2024 06:15:39
%S A055436 11,42,93,164,255,366,497,648,819,10010,12111,14412,16913,19614,22515,
%T A055436 25616,28917,32418,36119,40020,44121,48422,52923,57624,62525,67626,
%U A055436 72927,78428,84129,90030,96131,102432,108933,115634,122535,129636,136937,144438,152139
%N A055436 a(n) = concatenation of n^2 and n.
%F A055436 a(n) = n^2*floor(log_10(n) + 1) + n.
%F A055436 a(n) = A055437(n) if 1 <= n < 10, a(n) = A055438(n) if 10 <= n < 100.
%p A055436 a:= n-> parse(cat(n*n, n)):
%p A055436 seq(a(n), n=1..100); # _Alois P. Heinz_, Jan 03 2015
%t A055436 Table[n^2*10^IntegerLength[n] + n, {n, 36}] (* _Jayanta Basu_, Jul 12 2013 *)
%t A055436 Table[FromDigits[Join[IntegerDigits[n^2], IntegerDigits[n]]],{n, 40}] (* _Vincenzo Librandi_, Jan 03 2015 *)
%o A055436 (Magma) [Seqint(Intseq(n) cat Intseq(n^2)): n in [1..40]]; // _Vincenzo Librandi_, Jan 03 2015
%Y A055436 Cf. A053061, A055437 (10n^2+n), A055438 (100n^2+n).
%K A055436 base,easy,nonn
%O A055436 1,1
%A A055436 _Henry Bottomley_, May 18 2000