Search: id:A152988
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%I A152988
%S A152988 0,0,0,0,7,47,193,236,1579,4195,18461,62143,275781,1131909,7434169,
%T A152988 10522660,72469339,268486155,1442237845,4284330539,18146555293,
%U A152988 62021099893,248289236937,798007352239,2832660377605,11922780595861
%N A152988 Sum of proper divisors minus the number of proper divisors of Catalan 
               number A000108(n).
%F A152988 a(n) = A001065(A000108(n))-A032741(A000108(n)) = A152770(A000108(n)).
%e A152988 a(5)=47 because A000108(5)=42 has 7 proper divisors: 1,2,3,6,7,14,21 
               and 1+2+3+6+7+14+21-7=47. [From Emeric Deutsch (deutsch(AT)duke.poly.edu), 
               Dec 31 2008]
%p A152988 with(numtheory): seq(sigma(binomial(2*n, n)/(n+1))-binomial(2*n, n)/(n+1)-tau(binomial(2*n, 
               n)/(n+1))+1, n = 1 .. 27); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), 
               Dec 31 2008]
%Y A152988 Cf. A000005, A000108, A000203, A001065, A032741, A152770.
%Y A152988 Sequence in context: A142185 A158914 A046872 this_sequence A009202 A093112 
               A091516
%Y A152988 Adjacent sequences: A152985 A152986 A152987 this_sequence A152989 A152990 
               A152991
%K A152988 nonn
%O A152988 0,5
%A A152988 Omar E. Pol (info(AT)polprimos.com), Dec 20 2008, Jan 07 2009
%E A152988 Extended by Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 31 2008

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