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 A381835 #6 Mar 09 2025 12:57:40 %S A381835 2,4,10,15,21,28,33,39,57,72,82,87,93,111,126,144,165,180,198,244,249, %T A381835 255,273,288,306,327,342,360,414,459,489,504,522,576,621,675,730,735, %U A381835 741,759,774,792,813,828,846,900,945,975,990,1008,1062,1107,1161,1224,1269,1323 %N A381835 k/9 is in this list if k > 3 and A053735(k) = A007949(k), i.e. if digitsum(k, 3) = valuation(k, 3). %t A381835 Select[Range[9, 12000, 9], DigitSum[#, 3] == IntegerExponent[#, 3] &] / 9 %Y A381835 Cf. A053735, A007949, A381838. %Y A381835 Cf. A381834 (base = 4), A381833 (base = 5). %K A381835 nonn,base %O A381835 0,1 %A A381835 _Peter Luschny_, Mar 09 2025