A286627 - OEIS

%I #16 Jul 02 2017 03:59:20

%S 1,0,1,0,2,0,1,1,1,1,1,0,2,0,1,0,4,1,1,0,1,0,1,1,0,1,0,1,2,1,1,0,1,2,

%T 1,0,2,0,1,1,3,0,1,0,1,0,1,0,1,0,2,1,2,0,1,1,1,1,1,0,2,0,2,0,2,0,1,0,

%U 1,1,1,1,3,1,0,2,1,1,1,0,0,1,1,1,3,0,1,1,3,1,1,0,1,0,1,0,5,1,1,0,2,1,1,1,1,1,1,1,2,1,1,0,4,0,1,0,2,0,2,1,0

%N a(n) = exponent of the highest power of A000005(n) (number of divisors of n) dividing A000010(n) (totient function phi), a(1) = 1.

%C a(1) = 1 by convention.

%H Antti Karttunen, <a href="/A286627/b286627.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A286561(A000010(n), A000005(n)).

%e A000005(5) = 2, A000010(5) = 4, 2^2 is the highest power of 2 which divides 4, thus a(5) = 2.

%e A000005(6) = 4, A000010(6) = 2, 4^0 = 1 is the highest power of 4 which divides 2, thus a(6) = 0.

%o (PARI) A286627(n) = valuation(eulerphi(n), numdiv(n));

%Y Cf. A000005, A000010, A286561, A286628, A289276.

%Y Cf. A015733 (positions of zeros), A020491 (of nonzeros).

%K nonn

%O 1,5

%A _Antti Karttunen_, Jun 30 2017