Search: id:A085721 Results 1-1 of 1 results found. %I A085721 %S A085721 4,6,9,25,35,49,121,143,169,289,323,361,391,437,493,527,529,551,589,667, %T A085721 713,841,899,961,1369,1517,1591,1681,1739,1763,1849,1927,1961,2021,2173, %U A085721 2183,2209,2257,2279,2419,2491,2501,2537,2623,2773,2809 %N A085721 Semiprimes whose prime factors have an equal number of digits in binary representation. %H A085721 Dario A. Alpern, Brilliant Numbers. %e A085721 A078972(35) = 527 = 17*31 -> 10001*11111, therefore 527 is a term; %e A085721 A078972(37) = 533 = 13*41 -> 1101*101001, therefore 533 is not a term; %e A085721 A001358(1920) = 7169 = 67*107 -> 1000011*1101011: therefore 7169 a term, but not of A078972. %Y A085721 Cf. A078972, A001358, A007088, A070939, A055642. %Y A085721 Sequence in context: A084994 A046328 A046376 this_sequence A081614 A107665 A085733 %Y A085721 Adjacent sequences: A085718 A085719 A085720 this_sequence A085722 A085723 A085724 %K A085721 nonn %O A085721 1,1 %A A085721 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 20 2003 Search completed in 0.001 seconds