Search: id:A088274 Results 1-1 of 1 results found. %I A088274 %S A088274 1,2,4,8,9,24,60,110,134,222,412,700,999,1383,5076,5543,6344,14600, %T A088274 15093,21717,23636,30221,50711 %N A088274 Numbers n such that 10^n + 7 is prime. %C A088274 No others less than 59500. %H A088274 G. L. Honaker, Jr. and Chris Caldwell, eds., Prime Curios! %H A088274 Makoto Kamada, Factorizations of 100...007. %H A088274 Sabin Tabiraca and Kieran Reynolds, Lacunary Prime Numbers. %H A088274 Index entries for primes involving repunits. %e A088274 8 is a member since 10^8 + 7 = 100000007 is a prime. %t A088274 Do[ If[ PrimeQ[ 10^n + 7], Print[n]], {n, 0, 10000}] (from Robert G. Wilson v Dec 16 2004) %Y A088274 Cf. A088275, A049054. %Y A088274 Sequence in context: A111261 A046685 A140141 this_sequence A118418 A074810 A028984 %Y A088274 Adjacent sequences: A088271 A088272 A088273 this_sequence A088275 A088276 A088277 %K A088274 nonn %O A088274 1,2 %A A088274 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 28 2003 %E A088274 a(7) - a(14) from Ray Chandler (rayjchandler(AT)sbcglobal.net), Oct 09 2003 %E A088274 a(15) - a(19) from Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 18 2005 %E A088274 Corrected and extended by Jason Earls (zevi_35711(AT)yahoo.com), Nov 27 2007 and Dec 07 2007. (14600 was missing and 23636 and 50711 is new. These are presently only probable primes, found with WinPFGW.) %E A088274 Missing term 30221 added by Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008 Search completed in 0.002 seconds