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A056670 Largest prime factor of which the exponent exceeds 1 among prime factors of central binomial coefficient, C(n, floor(n/2)); largest non-unitary prime factor of A001405(n); or the maximal prime divisor of the largest square divisor(A056057(n)) of C(n, floor(n/2)). 0

%I

%S 1,1,1,1,1,2,1,1,3,3,1,2,2,2,3,3,1,2,1,2,2,2,1,2,5,5,5,5,3,3,3,3,3,3,

%T 5,5,5,5,3,3,2,2,2,2,5,5,5,5,7,7,7,7,7,7,2,2,2,2,2,2,2,2,7,7,7,7,7,7,

%U 3,3,1,2,2,2,5,5,7,7,7,7,7,7,3,3,5,5,5,5,3,3,7,7,7,7,7,7,5,5,3,3,3,3,3,3,3

%N Largest prime factor of which the exponent exceeds 1 among prime factors of central binomial coefficient, C(n, floor(n/2)); largest non-unitary prime factor of A001405(n); or the maximal prime divisor of the largest square divisor(A056057(n)) of C(n, floor(n/2)).

%e n=28: binomial(28,14) = 2*2*2*3*3*3*5*5*17*19*23, so a(28)=5;

%e n=342: C(342,171)=32*F, where F is squarefree, so a(341)=2.

%Y Cf. A001405, A056057, A056175.

%K nonn

%O 1,6

%A _Labos Elemer_, Aug 10 2000

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Last modified July 23 12:19 EDT 2021. Contains 346259 sequences. (Running on oeis4.)