Search: id:A062700
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%I A062700
%S A062700 3,7,13,31,31,127,307,1093,1723,2801,3541,8191,5113,8011,10303,19531,
%T A062700 17293,28057,30941,30103,131071,88741,86143,147073,524287,292561,
%U A062700 459007,492103,797161,552793,579883,598303,684757,704761,732541,735307
%N A062700 Terms of A000203 that are prime.
%C A062700 Sorted and uniqued, this gives A023195.
%H A062700 Harry J. Smith, <a href="b062700.txt">Table of n, a(n) for n=1,...,100</
               a>
%e A062700 sigma(2) = 3, sigma(4) = 7, sigma(9) = 13 are the first three prime terms 
               of A000203. Hence the sequence starts 3, 7, 13.
%o A062700 (MAGMA) [ c: n in [1..1000000] | IsPrime(c) where c:=SumOfDivisors(n) 
               ]; [From Klaus Brockhaus, Oct 21 2009]
%o A062700 (PARI) je=[]; for(n=1,1000000, if(isprime(sigma(n)),je=concat(je, sigma(n)))); 
               je
%o A062700 (PARI) { n=0; for (m=1, 10^9, if(isprime(a=sigma(m)), write("b062700.txt", 
               n++, " ", a); if (n==100, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), 
               Aug 09 2009]
%Y A062700 Cf. A000203 (sigma(n), sum of divisors of n), A034885 (record values 
               of sigma(n)), A023195 (prime numbers that are the sum of the divisors 
               of some n), A100382 (record values of A062700).
%Y A062700 Sequence in context: A025249 A147098 A109291 this_sequence A136060 A023227 
               A031157
%Y A062700 Adjacent sequences: A062697 A062698 A062699 this_sequence A062701 A062702 
               A062703
%K A062700 nonn
%O A062700 1,1
%A A062700 Jason Earls (zevi_35711(AT)yahoo.com), Jul 11 2001
%E A062700 Edited by Klaus Brockhaus, Oct 21 2009

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