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 A381837 #10 Mar 09 2025 12:57:56 %S A381837 1,4,8,16,20,32,48,64,68,80,96,128,144,192,256,260,272,288,320,336, %T A381837 384,448,512,528,576,640,768,832,1024,1028,1040,1056,1088,1104,1152, %U A381837 1216,1280,1296,1344,1408,1536,1600,1792,2048,2064,2112,2176,2304,2368,2560,2816 %N A381837 k/16 is in this list if A053737(k) < A235127(k), i.e. if digitsum(k, 4) < valuation(k, 4). %p A381837 aList := upto -> local k; [seq(k/16, k in select(n -> add(convert(n, base, 4)) < padic[ordp](n, 4), [seq(16..upto,16)]))]: aList(46000); %t A381837 Select[Range[46000],DigitSum[#,4]<IntegerExponent[#,4] &]/16 (* _Stefano Spezia_, Mar 08 2025 *) %o A381837 (SageMath) %o A381837 def aList(upto, b): return [n/b^2 for n in srange(b^2, upto, b^2) if sum(n.digits(b)) < valuation(n, b)] %o A381837 print(aList(46000, 4)) %Y A381837 Cf. A053737, A235127. %Y A381837 Cf. A371176 (base 2), A381838 (base 3), A381836 (base 5). %K A381837 nonn,base %O A381837 1,2 %A A381837 _Peter Luschny_, Mar 08 2025