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A065425 Smallest odd prime greater than n such that the decimal expansion of its base n conversion is also prime. 0

%I #5 Mar 31 2012 13:20:44

%S 3,67,5,13,7,17,11,37,11,31,13,29,17,41,17,37,19,41,23,53,23,113,31,

%T 53,29,109,29,61,31,71,41,89,37,73,37,83,41,89,41,109,43,89,47,101,47,

%U 97,61,101,53,113,53,109,61,113,59,137,59,127,61,131,71,137,67,139,67,137

%N Smallest odd prime greater than n such that the decimal expansion of its base n conversion is also prime.

%C For bases above ten, use multidigit numbers to represent the new number. See the example.

%e a(15) = 41. 17d = 12, 19d = 14, 23d = 18, 29d = 114, 31d = 21 and 37d = 27, all of which are composite. But 41d = 211 which is a prime.

%t Do[ k = PrimePi[n] + 1; While[ !PrimeQ[ FromDigits[ IntegerDigits[ Prime[k], n]]], k++ ]; Print[ Prime[k]], {n, 2, 50} ]

%Y Cf. A065720 - A065727.

%K base,nonn

%O 2,1

%A _Robert G. Wilson v_, Nov 15 2001

%E More terms from _David Wasserman_, Aug 30 2002

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