login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A057645 Initial prime in first sequence of n primes congruent to 2 modulo 9. 0
2, 5483, 25373, 182243, 5379113, 5379113, 1734847733, 12196390601, 17619405959, 213529133423, 2732797330031 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..11.

J. K. Andersen, Consecutive Congruent Primes.

EXAMPLE

a(2) = 5483 because this number is the first in a sequence of 2 consecutive primes all of the form 9n + 2.

MATHEMATICA

NextPrime[ n_Integer ] := Module[ {k = n + 1}, While[ ! PrimeQ[ k ], k++ ]; Return[ k ] ]; PrevPrime[ n_Integer ] := Module[ {k = n - 1}, While[ ! PrimeQ[ k ], k-- ]; Return[ k ] ]; p = 0; Do[ a = Table[ -1, {n} ]; k = Max[ 1, p ]; While[ Union[ a ] != {2}, k = NextPrime[ k ]; a = Take[ AppendTo[ a, Mod[ k, 9 ] ], -n ] ]; p = NestList[ PrevPrime, k, n ]; Print[ p[ [ -2 ] ] ]; p = p[ [ -1 ] ], {n, 1, 6} ] a(7) > 331804250.

CROSSREFS

Sequence in context: A153737 A078933 A064029 * A129060 A190127 A099690

Adjacent sequences:  A057642 A057643 A057644 * A057646 A057647 A057648

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Oct 11 2000

EXTENSIONS

More terms from Jens Kruse Andersen, May 31 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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 02:10 EDT 2019. Contains 322380 sequences. (Running on oeis4.)