Search: id:A129621
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%I A129621
%S A129621 2,3,5,7,11,13,17,19,23,29,37,41,43,59,61,67,71,73,83,97,101,103,107,
%T A129621 109,113,127,131,137,139,151,157,163,173,179,181,193,197,199,227,229,
%U A129621 239,241,257,263,269,277,281,283,293,307,311,313,317,331,347,349,353
%N A129621 Primes p such that at least one of k-1 and k+1 is prime, where k = sum 
               of the two neighboring primes of 3*p.
%e A129621 29*3 = 87, neighboring primes are 83 and 89 which sum to 172; 173 is 
               prime, hence 29 is in the sequence.
%e A129621 31*3 = 93, neighboring primes are 89 and 97 which sum to 186; neither 
               185 nor 187 is prime, hence 31 is not in the sequence.
%e A129621 1091*3 = 3273, neighboring primes are 3271 and 3299 which sum to 6570; 
               both 6569 and 6571 are prime, hence 1091 is in the sequence.
%o A129621 (PARI) {m=360; forprime(p=2, m, d=3*p; k=precprime(d)+nextprime(d); if(isprime(k-1)||isprime(k+1), 
               print1(p, ",")))} /* Klaus Brockhaus, Jun 05 2007 */
%Y A129621 Cf. A127566.
%Y A129621 Sequence in context: A095323 A100370 A095319 this_sequence A077500 A036955 
               A040179
%Y A129621 Adjacent sequences: A129618 A129619 A129620 this_sequence A129622 A129623 
               A129624
%K A129621 nonn
%O A129621 1,1
%A A129621 J. M. Bergot (thekingfishb(AT)yahoo.ca), May 30 2007
%E A129621 Edited and extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), 
               Jun 05 2007

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