login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

The maximal exponent in the prime factorization of the largest square dividing n.
5

%I #9 May 08 2024 08:53:02

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

%T 0,2,0,0,0,2,0,0,0,2,2,0,0,4,2,2,0,2,0,2,0,2,0,0,0,2,0,0,2,6,0,0,0,2,

%U 0,0,0,2,0,0,2,2,0,0,0,4,4,0,0,2,0,0,0

%N The maximal exponent in the prime factorization of the largest square dividing n.

%H Amiram Eldar, <a href="/A372602/b372602.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A051903(A008833(n)).

%F a(n) = A052928(A051903(n)).

%F Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = 2 * Sum_{i>=1} (1 - (1/zeta(2*i))) = 0.98112786070359477197... .

%t f[n_] := 2 * Floor[n/2]; a[n_] := f[Max[FactorInteger[n][[;; , 2]]]]; a[1] = 0; Array[a, 100]

%o (PARI) s(n) = n \ 2 * 2;

%o a(n) = if(n>1, s(vecmax(factor(n)[,2])), 0);

%Y Cf. A008833, A051903, A052928.

%Y Similar sequences: A007424, A368781, A372601, A372603, A372604.

%K nonn,easy

%O 1,4

%A _Amiram Eldar_, May 07 2024