cp's OEIS Frontend

A356167 Greatest common divisor of A003961(n) and the smallest positive k such that n divides k*A003961(k), where A003961 is fully multiplicative with a(p) = nextprime(p).

%I A356167 #8 Jul 28 2022 21:16:10
%S A356167 1,1,1,1,1,1,1,1,1,3,1,1,1,1,1,1,1,1,1,3,5,1,1,1,1,1,1,1,1,3,1,1,1,1,
%T A356167 1,1,1,1,1,3,1,5,1,1,1,1,1,1,1,3,1,1,1,1,7,1,1,1,1,3,1,1,5,1,1,1,1,1,
%U A356167 1,1,1,1,1,1,1,1,1,1,1,3,1,1,1,5,1,1,1,1,1,3,11,1,1,1,1,1,1,1,1,9,1,1,1,1,5
%N A356167 Greatest common divisor of A003961(n) and the smallest positive k such that n divides k*A003961(k), where A003961 is fully multiplicative with a(p) = nextprime(p).
%H A356167 Antti Karttunen, <a href="/A356167/b356167.txt">Table of n, a(n) for n = 1..65537</a>
%H A356167 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%F A356167 a(n) = gcd(A003961(n), A356164(n)).
%o A356167 (PARI)
%o A356167 A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
%o A356167 A356167(n) = for(k=1, oo, if((k*A003961(k))%n==0, return(gcd(A003961(n),k))));
%Y A356167 Cf. A003961, A191002, A356164, A356165, A356166.
%Y A356167 Cf. also A345993.
%K A356167 nonn,look
%O A356167 1,10
%A A356167 _Antti Karttunen_, Jul 28 2022