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 A387056 #7 Aug 17 2025 11:17:56 %S A387056 1,2,4,8,12,16,20,24,28,32,36,40,44,48,52,56,64,68,72,76,80,88,92,96, %T A387056 100,104,112,116,124,128,136,144,148,152,160,164,172,176,184,188,192, %U A387056 196,200,208,212,224,232,236,240,244,248,256,268,272,284,288,292,296 %N A387056 Numbers k that are divisible by the number of infinitary divisors of k. %C A387056 First differs from A048166 at n = 27: A048166(27) = 108 is not a term of this sequence. %C A387056 This sequence is infinite. For example, if p is a prime, then 8*p is a term. %H A387056 Amiram Eldar, <a href="/A387056/b387056.txt">Table of n, a(n) for n = 1..10000</a> %t A387056 f[p_, e_] := 2^DigitCount[e, 2, 1]; id[1] = 1; id[n_] := Times @@ f @@@ FactorInteger[n]; q[k_] := Divisible[k, id[k]]; Select[Range[300], q] %o A387056 (PARI) isok(k) = !(k % vecprod(apply(x -> 2^hammingweight(x), factor(k)[, 2]))); %Y A387056 A387057 is a subsequence. %Y A387056 Cf. A033950, A037445, A048166. %K A387056 nonn,easy %O A387056 1,2 %A A387056 _Amiram Eldar_, Aug 15 2025