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A114016 Least n-digit prime which differs from the next prime at every corresponding digit. 1

%I

%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

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Last modified September 29 16:13 EDT 2020. Contains 337432 sequences. (Running on oeis4.)