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 A037428 #21 Jan 01 2023 13:20:10 %S A037428 1,2,3,13,31,123,203,231,1031,1103,1120,1203,1230,1303,2103,2120,2201, %T A037428 2300,2301,2302,2303,3012,3020,3021,3022,3023,3100,3101,3102,3103, %U A037428 3200,3201,3202,3203,3320,10023,10032,10123,10132,10232,10323,10332 %N A037428 Positive numbers having the same set of digits in base 4 and base 10. %H A037428 John Cerkan, <a href="/A037428/b037428.txt">Table of n, a(n) for n = 1..10000</a> %e A037428 1103 is in the sequence because 1103 in base 4 is 101033. %t A037428 Select[Range[33333],Union[IntegerDigits[#]]==Union[IntegerDigits[#,4]]&] (* _Harvey P. Dale_, Jan 01 2023 *) %o A037428 (PARI) is(n)=Set(digits(n, 4))==Set(digits(n)) \\ _Charles R Greathouse IV_, Feb 11 2017 %Y A037428 Subsequence of A007090 and A037392. %K A037428 nonn,base %O A037428 1,2 %A A037428 _Clark Kimberling_ %E A037428 Corrected by _Don Reble_, Apr 28 2006 %E A037428 Edited by _John Cerkan_, Feb 09 2017