C(n) = R(2n)/R(n) C( 1) = 11 = prime C( 2) = 101 = prime C( 3) = 1001 = 7*11*13 C( 4) = 10001 = 73*137 C( 5) = 100001 = 11*9091 C( 6) = 1000001 = 101*9901 C( 7) = 10000001 = 11*909091 C( 8) = 100000001 = 17*5882353 C( 9) = 1000000001 = 7*11*13*19*52579 C(10) = 10000000001 = 101*3541*27961 C(11) = 100000000001 = 11^2*23*4093*8779 C(12) = 1000000000001 = 73*137*99990001 C(13) = 10000000000001 = 11*859*1058313049 C(14) = 100000000000001 = 29*101*281*121499449 C(15) = 1000000000000001 = 7*11*13*211*241*2161*9091 C(16) = 10000000000000001 = 353*449*641*1409*69857 C(17) = 100000000000000001 = 11*103*4013*21993833369 C(18) = 1000000000000000001 = 101*9901*999999000001 C(19) = 10000000000000000001 = 11*909090909090909091 C(20) = 100000000000000000001 = 73*137*1676321*5964848081 C(21) = 1000000000000000000001 = 7^2*11*13*127*2689*459691*909091 C(22) = 10000000000000000000001 = 89*101*1052788969*1056689261 C(23) = 100000000000000000000001 = 11*47*139*2531*549797184491917 C(24) = 1000000000000000000000001 = 17*5882353*9999999900000001 C(25) = 10000000000000000000000001 = 11*251*5051*9091*78875943472201 C(26) = 100000000000000000000000001 = 101*521*1900381976777332243781 C(27) = 1000000000000000000000000001 = 7*11*13*19*52579*70541929*14175966169 C(28) = 10000000000000000000000000001 = 73*137*7841*127522001020150503761 C(29) = 100000000000000000000000000001 = 11*59*154083204930662557781201849 C(30) = 1000000000000000000000000000001 = 61*101*3541*9901*27961*4188901*39526741 C(31) = 10000000000000000000000000000001 = 11*909090909090909090909090909091 C(32) = 100000000000000000000000000000001 = 19841*976193*6187457*834427406578561 C(33) = 1000000000000000000000000000000001 = 7*11^2*13*23*4093*8779*599144041*183411838171 C(34) = 10000000000000000000000000000000001 = 101*28559389*1491383821*2324557465671829 C(35) = 100000000000000000000000000000000001 = 11*9091*909091*4147571*265212793249617641 C(36) = 1000000000000000000000000000000000001 = 73*137*3169*98641*99990001*3199044596370769 C(37) = 10000000000000000000000000000000000001 = 11*7253*422650073734453*296557347313446299 C(38) = 100000000000000000000000000000000000001 = 101*722817036322379041*1369778187490592461 C(39) = 1000000000000000000000000000000000000001 = 7*11*13^2*157*859*6397*216451*1058313049*388847808493 C(40) = 10000000000000000000000000000000000000001 = 17*5070721*5882353*19721061166646717498359681 C(41) = 100000000000000000000000000000000000000001 = 11*2670502781396266997*3404193829806058997303 C(42) = 1000000000000000000000000000000000000000001 = 29*101*281*9901*226549*121499449*4458192223320340849 C(43) = 10000000000000000000000000000000000000000001 = 11*57009401*2182600451*7306116556571817748755241 C(44) = 100000000000000000000000000000000000000000001 = 73*137*617*16205834846012967584927082656402106953 C(45) = 1000000000000000000000000000000000000000000001 = 7*11*13*19*211*241*2161*9091*29611*52579*3762091*8985695684401 C(46) = 10000000000000000000000000000000000000000000001 = 101*1289*18371524594609*4181003300071669867932658901 C(47) = 100000000000000000000000000000000000000000000001 = 11*6299*4855067598095567*297262705009139006771611927 C(48) = 1000000000000000000000000000000000000000000000001 = 97*353*449*641*1409*69857*206209*66554101249*75118313082913 C(49) = 10000000000000000000000000000000000000000000000001 = 11*197*909091*5076141624365532994918781726395939035533 C(50) = 100000000000000000000000000000000000000000000000001 = 101*3541*27961*60101*7019801*14103673319201*1680588011350901