This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A120825 Number of digits of primes with n consecutive digits ascending beginning with the digit seven. 8
 1, 5, 15, 51 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Digits are in ascending order beginning with 7 and after 9 comes 0. 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. LINKS EXAMPLE 1 is here because 7 is prime. 5 is here because 78901 is prime. 15 is here because 789012345678901 is a prime. 51 is here because 789012345678901234567890123456789012345678901234567 is prime. MATHEMATICA fQ[n_] := PrimeQ@ FromDigits@ Mod[6+Range@n, 10]; lst = {}; Do[ If[fQ@n, AppendTo[lst, n]; Print@n], {n, 5000}]; lst CROSSREFS Cf. A006055, A120819, A120820, A120821, A120822, A120823, A120824, A120826, A120827. Sequence in context: A034539 A029609 A014274 * A199985 A255442 A149576 Adjacent sequences:  A120822 A120823 A120824 * A120826 A120827 A120828 KEYWORD base,hard,nonn AUTHOR Robert G. Wilson v, Jul 05 2006 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 21 15:11 EST 2019. Contains 320374 sequences. (Running on oeis4.)