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 A383325 #6 Apr 25 2025 16:00:15 %S A383325 3,4,6,7,8,9,10,11,12,13,14,15,17,18,19,20,21,22,23,24,25,26,27,28,29, %T A383325 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,50,51,52,53, %U A383325 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72 %N A383325 Numbers not of the form round(3^k/5). Complement of A383324. %F A383325 a(n) = m+1 if m >= floor((3^k+2)/5) and a(n) = m otherwise where k = floor(log_3(5*n+8))+1 and m = n-1+k. %o A383325 (Python) %o A383325 from sympy import integer_log %o A383325 def A383325(n): return (m:=n-1+(k:=integer_log(5*n+8,3)[0]+1))+(m>=(3**k+2)//5) %Y A383325 Cf. A383324. %K A383325 nonn %O A383325 1,1 %A A383325 _Chai Wah Wu_, Apr 23 2025