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 A344877 #10 Jun 30 2021 19:48:05
%S A344877 1,1,1,1,1,6,1,1,1,2,1,2,1,2,1,1,1,6,1,4,3,2,1,6,1,2,1,14,1,6,1,1,1,2,
%T A344877 1,4,1,2,3,20,1,6,1,2,1,2,1,2,1,2,1,4,1,6,5,2,3,2,1,4,1,2,3,1,1,6,1,4,
%U A344877 1,2,1,24,1,2,3,2,1,6,1,4,1,2,1,84,1,2,1,2,1,6,1,2,3,2,1,6,1,2,1,4,1,6,1,4,3
%N A344877 a(n) = gcd(n, A344875(n)), where A344875 is multiplicative with a(2^e) = 2^(1+e) - 1, and a(p^e) = p^e -1 for odd primes p.
%H A344877 Antti Karttunen, <a href="/A344877/b344877.txt">Table of n, a(n) for n = 1..10000</a>
%H A344877 Antti Karttunen, <a href="/A344877/a344877.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%t A344877 f[2, e_] := 2^(e + 1) - 1; f[p_, e_] := p^e - 1; a[1] = 1; a[n_] := GCD[n, Times @@ f @@@ FactorInteger[n]]; Array[a, 100] (* _Amiram Eldar_, Jun 03 2021 *)
%o A344877 (PARI)
%o A344877 A344875(n) = { my(f=factor(n)~); prod(i=1, #f, (f[1, i]^(f[2, i]+(2==f[1, i]))-1)); };
%o A344877 A344877(n) = gcd(n, A344875(n));
%Y A344877 Cf. A344875.
%Y A344877 Cf. also A323409.
%K A344877 nonn
%O A344877 1,6
%A A344877 _Antti Karttunen_, Jun 03 2021