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 A305677 #26 Mar 25 2024 06:36:02
%S A305677 1,2,8,1,64,256,2048,4,1,131072,262144,32,8388608,33554432,134217728,
%T A305677 1,2147483648,8,34359738368,1024,549755813888,4398046511104,
%U A305677 17592186044416,8192,2,1125899906842624,32,65536,72057594037927936,576460752303423488
%N A305677 Number of subsets of {n+1, n+2, ..., A072905(n)-1} whose product has the same squarefree part as n.
%C A305677 Conjecture: a(n) > 0.
%C A305677 If the conjecture is true, all terms are powers of two, and a(n) >= A259527(n).
%C A305677 a(n) = 0 if and only if A066400(n) = 2.
%C A305677 a(n) = 0 if and only if A255167(n) = 0.
%C A305677 a(n) <= 2^(A067722(n) - 1). - _Peter Kagey_, Nov 13 2018
%H A305677 Peter Kagey, <a href="/A305677/b305677.txt">Table of n, a(n) for n = 1..200</a>
%e A305677 For n = 3, the a(3) = 8 subsets of {4, 5, ..., 11} with a product with squarefree part of 3 are {4, 5, 6, 9, 10}, {4, 5, 6, 10}, {4, 6, 8}, {4, 6, 8, 9}, {5, 6, 9, 10}, {5, 6, 10}, {6, 8}, and {6, 8, 9}.
%Y A305677 Cf. A005117, A006255, A066400, A072905, A255167.
%K A305677 nonn
%O A305677 1,2
%A A305677 _Peter Kagey_, Jun 08 2018