Search: id:A156658 Results 1-1 of 1 results found. %I A156658 %S A156658 2,3,5,7,11,23,29,41,47,53,59,83,89,107,113,131,167,173,179,191,227,233, %T A156658 239,251,263,281,293,347,359,383,419,431,443,467,479,491,503,509,563, %U A156658 587,593,641,653,659,683,719,743,761,809,839,863,887,911,953,983,1013 %N A156658 Primes p such that also 2*p+1 or (p-1)/2 is prime. %C A156658 Union of A005384 and A005385; %C A156658 A156660(a(n)) + A156659(a(n)) > 0; %C A156658 primes occuring in Cunningham chains of the first kind. %C A156658 A156876 gives the number of these numbers <= n. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 18 2009] %H A156658 Wikipedia, Sophie Germain prime %H A156658 Wikipedia, Safe prime %H A156658 Wikipedia, Cunningham chain %Y A156658 A059500. %Y A156658 Sequence in context: A089392 A089695 A070027 this_sequence A118723 A118721 A094318 %Y A156658 Adjacent sequences: A156655 A156656 A156657 this_sequence A156659 A156660 A156661 %K A156658 nonn %O A156658 1,1 %A A156658 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 13 2009 Search completed in 0.003 seconds