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 A166498 #20 May 25 2025 17:51:13 %S A166498 0,1,4,9,10,11,14,16,19,25,36,40,41,44,49,64,81,90,91,94,99,100,101, %T A166498 104,109,110,111,114,116,119,121,125,136,140,141,144,149,160,161,164, %U A166498 169,181,190,191,194,196,199,225,250,251,254,256,259,289,324,360,361 %N A166498 Integers formed by concatenating squares. %e A166498 11 being the concatenation of 1 and 1, both squares, is in the sequence. %e A166498 120 is not in the sequence as none of 2, 12, 20 and 120 are squares. - corrected by _Peter Munn_, Nov 17 2017 %t A166498 Take[FromDigits[Flatten[IntegerDigits/@#]]&/@Tuples[Range[0,20]^2,3]//Union,60] (* _Harvey P. Dale_, May 25 2025 *) %Y A166498 Cf. A000290 (squares), A152242 (integers formed by concatenating primes). %K A166498 base,nonn %O A166498 1,3 %A A166498 _Zak Seidov_, Oct 15 2009 %E A166498 Corrected and extended by _Michel Marcus_, Oct 16 2013 %E A166498 Mispositioning of example corrected by _Peter Munn_, Nov 17 2017