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A084217 Number of k's 1<=k<=n dividing the numerator of 2n-th Bernoulli number. 1

%I #5 Mar 30 2012 18:39:18

%S 1,1,1,2,1,2,1,1,1,2,1,2,2,2,1,2,1,2,1,1,2,2,1,3,2,1,2,2,1,2,1,2,2,4,

%T 1,2,2,2,1,2,1,2,2,2,2,2,1,3,1,2,3,2,1,2,2,2,2,2,1,2,2,1,1,4,2,2,2,2,

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

%N Number of k's 1<=k<=n dividing the numerator of 2n-th Bernoulli number.

%o (PARI) a(n)=sum(k=1,n,if(numerator(bernfrac(2*n))%k,0,1))

%K nonn

%O 1,4

%A _Benoit Cloitre_, Jun 21 2003

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Last modified April 25 03:15 EDT 2024. Contains 371964 sequences. (Running on oeis4.)