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 A383016 #11 Apr 29 2025 16:53:10 %S A383016 1,4,6,8,9,10,14,15,21,22,25,26,27,32,33,34,35,38,39,46,49,51,55,57, %T A383016 58,62,65,69,74,77,82,85,86,87,91,93,94,95,106,111,115,118,119,121, %U A383016 122,123,125,128,129,133,134,141,142,143,145,146,155,158,159,161,166 %N A383016 Numbers k such that A382883(k) = 1. %C A383016 See the comments in A382883. %F A383016 A382883 = this sequence union A383017 union A382943. %F A383016 Conjecture: A053810 is a subsequence. %t A383016 V[n_, e_] := If[e == 1, 1, IntegerExponent[n, e]]; f[n_] := f[n] = -DivisorSum[n, V[n, #] * f[#] &, # < n &]; f[1] = 1; Select[Range[200], f[#] == 1 &] (* _Amiram Eldar_, Apr 29 2025 *) %o A383016 (SageMath) %o A383016 def A383016List(upto): return [n for n in srange(1, upto) if A382883(n) == 1] %Y A383016 Cf. A382883, A382943, A383017, A053810, A162143. %K A383016 nonn %O A383016 1,2 %A A383016 _Peter Luschny_, Apr 12 2025