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 A386571 #9 Jul 30 2025 22:47:34
%S A386571 5,9,11,14,17,21,23,25,29,35,41,45,47,51,59,62,64,65,68,69,71,76,77,
%T A386571 79,95,101,103,105,118,119,125,128,149,152,154,155,161,163,184,188,
%U A386571 189,191,193,197,202,208,209,218,220,221,229,236,239,241,244,253,254,258
%N A386571 Numbers that are not of the form k - omega(k), where omega(k) is the number of distinct primes dividing k.
%C A386571 Luca (2005) proved that this sequence is infinite.
%H A386571 Amiram Eldar, <a href="/A386571/b386571.txt">Table of n, a(n) for n = 1..10000</a>
%H A386571 Florian Luca, <a href="https://doi.org/10.1007/s10474-005-0010-8">On numbers not of the form n-omega(n)</a>, Acta Mathematica Hungarica, Vol. 106, No. 1 (2005), pp. 117-135.
%t A386571 seq[lim_] := Complement[Range[lim], Table[k - PrimeNu[k], {k, 1, lim + Log2[lim]}]]; seq[300]
%o A386571 (PARI) list(lim) = setminus(vector(lim, i, i), Set(vector(lim + logint(lim, 2), i, i - omega(i))));
%Y A386571 Cf. A001221, A378993.
%Y A386571 Numbers not of the form k-f(k): A005278 (phi), A045765 (d), this sequence (omega), A386572 (Omega).
%K A386571 nonn
%O A386571 1,1
%A A386571 _Amiram Eldar_, Jul 26 2025