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A081810 If n = p_1^e_1 * ... * p_k^e_k, p_1 < ... < p_k primes, then a(n) = Max{ p_i*e_i }.

%I A081810 #18 Jul 19 2020 04:27:37
%S A081810 0,2,3,4,5,3,7,6,6,5,11,4,13,7,5,8,17,6,19,5,7,11,23,6,10,13,9,7,29,5,
%T A081810 31,10,11,17,7,6,37,19,13,6,41,7,43,11,6,23,47,8,14,10,17,13,53,9,11,
%U A081810 7,19,29,59,5,61,31,7,12,13,11,67,17,23,7,71,6,73,37,10,19,11,13,79,8,12
%N A081810 If n = p_1^e_1 * ... * p_k^e_k, p_1 < ... < p_k primes, then a(n) = Max{ p_i*e_i }.
%C A081810 If x and y are coprime then a(x*y) = max(a(x),a(y)). - _Robert Israel_, Nov 27 2017
%H A081810 Robert Israel, <a href="/A081810/b081810.txt">Table of n, a(n) for n = 1..10000</a>
%p A081810 f:= proc(n) max(seq(convert(t,`*`),t=ifactors(n)[2])) end proc:
%p A081810 f(1):= 0:
%p A081810 map(f, [$1..100]); # _Robert Israel_, Nov 27 2017
%t A081810 a[n_] := Module[{f = FactorInteger[n]}, Max[f[[All, 1]] f[[All, 2]]]];
%t A081810 Array[a, 100] (* _Jean-François Alcover_, Jul 19 2020 *)
%o A081810 (PARI) a(n)=local(f); if(n==1,0,f=factor(n); vecmax(vector(matsize(f)[1],k,f[k,1]*f[k,2])))
%Y A081810 Cf. A081811 (with min).
%K A081810 nonn
%O A081810 1,2
%A A081810 _Benoit Cloitre_, Apr 10 2003