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 A181816 #16 Jul 07 2019 13:36:18 %S A181816 1,1,1,2,1,2,1,2,12,1,4,2,12,1,4,2,12,1,4,24,2,360,8,12,1,4,24,2,360, %T A181816 8,12,1,4,24,2,360,8,144,12,1,48,4,720,16,24,2,360,8,144,12,1 %N A181816 a(n) is the smallest integer that, upon multiplying any divisor of A025487(n), produces a member of A025487. %C A181816 All terms also belong to A181818. Each member of A181818 appears infinitely often. a(A025487(m)) = a(A025487(n)) iff A025487(m) and A025487(n) have the same odd part (cf. A000265). %H A181816 Amiram Eldar, <a href="/A181816/b181816.txt">Table of n, a(n) for n = 1..10000</a> %F A181816 If A025487(n) = Product p(i)^e(i), then a(n) = Product A002110(i-1)^e(i); i.e., a(n) = A181811(A025487(n)). %F A181816 a(n) = A181817(n)/A025487(n). %e A181816 For any divisor d of 6 (d = 1, 2, 3, 6), 2*d (2, 4, 6, 12) is always a member of A025487. 2 is the smallest number with this relationship to 6; therefore, since 6 = A025487(4), a(4) = 2. %Y A181816 Cf. A000265, A025487, A181811, A181817, A181818. %K A181816 nonn %O A181816 1,4 %A A181816 _Matthew Vandermast_, Nov 30 2010