Search: id:A077816 Results 1-1 of 1 results found. %I A077816 %S A077816 1093,3279,3511,7651,10533,14209,17555,22953,31599,42627,45643,52665, %T A077816 68859,94797,99463,127881,136929,157995,228215,298389,410787,473985, %U A077816 684645,895167,1232361,2053935,2685501,3697083,3837523,6161805,11512569 %N A077816 Wieferich numbers: n such that 2^phi(n) == 1 modulo n^2. %C A077816 A077815(a(n))=1; %C A077816 The only known primes are a(1)=A001220(1)=1093 and a(3)=A001220(2)=3511, the Wieferich primes. %D A077816 R. Crandall and C. Pomerance, Prime Numbers: A Computational Perspective, Springer, NY, 2001; see p. 28. %H A077816 RICHARD CRANDALL, KARL DILCHER and CARL POMERANCE, A SEARCH FOR WIEFERICH AND WILSON PRIMES, Mathematics of Computation, Volume 66, 1997. %e A077816 A077815(3279) = 2^phi(3279) mod 3279*3279 = 2^phi(3*1093) mod 10751841 = 2^(3279*(1-1/3)*(1-1/1093)) mod 10751841 = 2^2184 mod 10751841 = 1, therefore 3279 is a term %Y A077816 Cf. A001220. %Y A077816 Sequence in context: A138698 A023698 A038469 this_sequence A001220 A115192 A091674 %Y A077816 Adjacent sequences: A077813 A077814 A077815 this_sequence A077817 A077818 A077819 %K A077816 nonn %O A077816 1,1 %A A077816 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 17 2002 %E A077816 More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 05 2005 %E A077816 More terms from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Jun 18 2005 Search completed in 0.001 seconds