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 A093394 #10 Oct 21 2019 02:20:47 %S A093394 1,1,1,2,1,1,3,2,1,4,1,2,15,1,1,6,1,4,21,2,1,8,5,2,27,4,1,30,1,1,33,2, %T A093394 35,12,1,2,39,8,1,42,1,4,45,2,1,16,7,10,51,4,1,54,55,8,57,2,1,60,1,2, %U A093394 63,1,65,66,1,4,69,70,1,24,1,2,75,4 %N A093394 a(n) is the GCD of n and the product of the anti-divisors of n. %C A093394 See A066272 for definition of anti-divisor. %F A093394 a(n) = gcd(n, A091507(n)). %e A093394 The anti-divisors of 18 are 4, 5, 7, 12. Hence a(18) = gcd(4*5*7*12, 18) = 6. %Y A093394 Cf. A066417, A091507, A093395, A093396. %K A093394 nonn %O A093394 3,4 %A A093394 _Lior Manor_, Mar 28 2004