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%I #10 Nov 30 2021 18:49:26
%S 1,2,1,3,1,3,5,4,4,4,7,5,6,7,5,7,8,7,9,8,11,11,8,7,9,11,8,13,12,11,12,
%T 11,12,12,14,13,15,15,11,13,14,18,15,15,15,14,17,14,17,18,18,20,17,19,
%U 19,19,18,19,21,19,19,21,20,22,18,21,24,22,26,24,20
%N Greatest number k such that A048784(n) / 2^k is an integer.
%C 2-adic valuation of A048784.
%C Property: a(n) > 0, that is A048784(n) is even, for n > 0.
%H Charles R Greathouse IV, <a href="/A213594/b213594.txt">Table of n, a(n) for n = 1..10000</a>
%e a(7) = 5 because A048784(7) / 2^5 = 32 / 32 = 1 is integer.
%p with(numtheory): for n from 1 to 100 do:ii:=0:for k from 500 by -1 to 1 while(ii=0) do: x:=evalf(tau(binomial(2*n,n))/2^k):if x=floor(x) then ii:=1: printf(`%d, `,k):else fi:od:od:
%o (PARI) a(n)=valuation(numdiv(binomial(2*n,n)),2) \\ _Charles R Greathouse IV_, Jun 15 2012
%Y Cf. A000005, A048784.
%K nonn
%O 1,2
%A _Michel Lagneau_, Jun 15 2012
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