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%I #9 Dec 05 2013 19:57:13
%S 2,19,199,1999,19997,199999,2999999,19999999,199999991,1999999973,
%T 19999999967,299999999989,1999999999981,19999999999997,
%U 399999999999997,1999999999999943,49999999999999993,199999999999999949,1999999999999999909,19999999999999999939
%N Least n-digit prime which differs from the next prime at every corresponding digit.
%C The corresponding next-primes are 3, 23, 211, 2003, 20011, 200003, 3000017, ... - _Michel Marcus_, Sep 15 2013
%e 1999 is a term as the next prime 2003 differs at every corresponding position (1,2), (9,0),(9,0),(9,3).
%o (PARI) ok(fp) = {fpa = precprime(fp); fpb = nextprime(fp); da = digits(fpa); db = digits(fpb); for (i=1, #da, if (da[i] == db[i], return (0));); return (fpa);}
%o a(n) = {if (n == 1, return (2)); for (i = 2, 9, if (p = ok(i*10^(n-1)), return(p));); return (0);} \\ _Michel Marcus_, Sep 15 2013
%Y Cf. A114017.
%K base,nonn
%O 1,1
%A _Amarnath Murthy_, Nov 12 2005
%E 2 more terms from _R. J. Mathar_, Aug 31 2007
%E More terms from _Michel Marcus_, Sep 15 2013