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 A037439 #18 Apr 24 2021 02:04:06 %S A037439 1,2,3,4,5,6,31,99,198,248,297,749,1163,1471,1498,1577,1831,2247,3413, %T A037439 3988,4473,4491,4500,4509,4788,4789,4790,4791,4792,4793,4794,6769, %U A037439 7311,7626,7698,7726,8290,8299,8535,9005,9038,9122,9172,9185,9192,9199,9248,9801 %N A037439 Positive numbers having the same set of digits in base 7 and base 9. %H A037439 John Cerkan, <a href="/A037439/b037439.txt">Table of n, a(n) for n = 1..10000</a> %e A037439 198 is in the sequence because 198 in base 7 is 402 and in base 9 it is 240. %t A037439 Select[Range[10^4], Union@ IntegerDigits[#, 7] == Union@ IntegerDigits[#, 9] &] (* _Michael De Vlieger_, Feb 18 2017 *) %o A037439 (PARI) isok(n) = Set(digits(n, 7)) == Set(digits(n, 9)); \\ _Michel Marcus_, Feb 18 2017 %Y A037439 Subsequence of A037403. %Y A037439 Cf. A007093, A007095. %K A037439 nonn,base %O A037439 1,2 %A A037439 _Clark Kimberling_ %E A037439 More terms from _Don Reble_, Apr 28 2006 %E A037439 Edited by _John Cerkan_, Feb 17 2017