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 A383304 #10 Apr 25 2025 10:30:42 %S A383304 0,13,26,31,39,62,93,123,132,144,213,225,231,246,252,264,267,276,288, %T A383304 312,321,348,369,384,396,414,426,438,441,462,483,522,624,627,639,642, %U A383304 672,693,726,762,828,834,843,882,936,963,1133,1223,1232,1313,1322,1331,1344,1434,1443 %N A383304 Nonnegative integers whose difference between the largest and smallest digits is equal to the arithmetic mean of its digits. %e A383304 144 is a term since 4 - 1 = 3 = (1 + 4 + 4)/3. %t A383304 Select[Range[0,1500], Max[d=IntegerDigits[#]]-Min[d]==Mean[d] &] %o A383304 (Python) %o A383304 def ok(n): return sum(d:=list(map(int, str(n)))) == (max(d) - min(d))*len(d) %o A383304 print([k for k in range(1500) if ok(k)]) # _Michael S. Branicky_, Apr 23 2025 %Y A383304 Cf. A037904, A054054, A054055, A179239, A371383, A371384, A383305. %Y A383304 Subsequence of A061383. %K A383304 nonn,base,easy %O A383304 1,2 %A A383304 _Stefano Spezia_, Apr 22 2025