A395052 - OEIS

%I #7 Apr 15 2026 10:04:13

%S 1,2,2,3,3,5,3,2,7,7,2,11,31,2,2,13,5,17,2,2,211,19,5,3,2311,3,2,23,3,

%T 29,5,53,509,3,3,31,277,17,3,37,11,41,53,5,27953,43,3,5,13,1877,17,47,

%U 7,3,11,31907,703763,53,5,59,34231,17,3,193,71,61,1877,22247,37,67,7,71,200560490131,7,31907,5,257,73

%N a(n) = A006530(A276085(n)), where A006530 gives the largest prime factor of n, and A276085 is fully additive with a(p) = p#/p.

%H Antti Karttunen, <a href="/A395052/b395052.txt">Table of n, a(n) for n = 2..465</a>

%F a(A000040(n)) = A008578(n).

%o (PARI)

%o A006530(n) = if(n>1, vecmax(factor(n)[, 1]), 1);

%o A276085(n) = { my(f=factor(n)); sum(k=1, #f~, f[k, 2]*prod(i=1,primepi(f[k, 1]-1),prime(i))); };

%o A395052(n) = A006530(A276085(n));

%Y Cf. A000040, A006530, A008578, A276085.

%Y Cf. also A394895, A395042.

%K nonn

%O 2,2

%A _Antti Karttunen_, Apr 15 2026