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%I #14 May 09 2014 02:45:49
%S 1,5,15,51
%N Number of digits of primes with n consecutive digits ascending beginning with the digit seven.
%C Digits are in ascending order beginning with 7 and after 9 comes 0.
%C The sequence "Primes with n consecutive digits descending beginning with the digit seven" has only two terms below 6001, namely 1 and 5, which represent the primes 7 and 76543, respectively.
%e 1 is here because 7 is prime.
%e 5 is here because 78901 is prime.
%e 15 is here because 789012345678901 is a prime.
%e 51 is here because 789012345678901234567890123456789012345678901234567 is prime.
%t fQ[n_] := PrimeQ@ FromDigits@ Mod[6+Range@n, 10]; lst = {}; Do[ If[fQ@n, AppendTo[lst, n]; Print@n], {n, 5000}]; lst
%Y Cf. A006055, A120819, A120820, A120821, A120822, A120823, A120824, A120826, A120827.
%K base,hard,nonn
%O 1,2
%A _Robert G. Wilson v_, Jul 05 2006
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