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 A280702 #11 Mar 09 2017 09:58:06
%S A280702 1,3,5,9,7,15,11,3,25,3,13,3,17,3,35,9,19,3,23,3,55,3,29,3,49,3,5,9,
%T A280702 31,3,37,3,5,3,77,15,41,3,5,9,43,3,47,3,5,3,53,3,121,147,5,153,59,3,
%U A280702 91,33,5,3,61,3,67,3,5,27,119,195,71,3,5,3,73,3,79,3,5,9,143,3,83,3,5,3,89,3,133,3,5,9,97,3,187,3,5,3,161
%N A280702 a(n) = gcd(A003961(n), A250469(n)).
%C A280702 For n > 1, a(n) > 1 because A020639(A003961(n)) = A020639(A250469(n)) = A003961(A020639(n)).
%H A280702 Antti Karttunen, <a href="/A280702/b280702.txt">Table of n, a(n) for n = 1..13330</a>
%F A280702 a(n) = gcd(A003961(n), A250469(n)).
%t A280702 f[n_] := f[n] = Which[n == 1, 1, PrimeQ@ n, NextPrime@ n, True, Times @@ Replace[FactorInteger[n], {p_, e_} :> f[p]^e, 1]]; g[n_] := If[n == 1, 0, PrimePi@ FactorInteger[n][[1, 1]]]; Function[s, MapIndexed[ GCD[ Lookup[s, g[First@ #2] + 1][[#1]] - Boole[First@ #2 == 1], f@ First@ #2] &, #] &@ Map[Position[Lookup[s, g@ #], #][[1, 1]] &, Range@ 120]]@ PositionIndex@ Array[g, 10^4] (* _Michael De Vlieger_, Mar 08 2017 *)
%o A280702 (Scheme) (define (A280702 n) (gcd (A003961 n) (A250469 n)))
%Y A280702 Cf. A003961, A020639, A250469, A280497, A280498, A280692, A280703, A280704, A283463, A283464.
%K A280702 nonn
%O A280702 1,2
%A A280702 _Antti Karttunen_, Mar 08 2017