login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A057634 Initial prime in first sequence of n primes congruent to 7 modulo 8. 0
7, 359, 1823, 79063, 272863, 989647, 10604519, 10604519, 309202951, 309202951, 1383423311, 21120585463, 534956098463, 534956098463, 534956098463, 925195153703, 74587805307479 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..17.

J. K. Andersen, Consecutive Congruent Primes.

EXAMPLE

a(4) = 79063 because this number is the first in a sequence of 4 consecutive primes all of the form 8n + 7.

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 ] != {7}, k = NextPrime[ k ]; a = Take[ AppendTo[ a, Mod[ k, 8 ]], -n ]]; p = NestList[ PrevPrime, k, n ]; Print[ p[[ -2 ] ]]; p = p[[ -1 ]], {n, 1, 8} ] a(9) > 115647000.

CROSSREFS

Sequence in context: A185062 A067556 A082098 * A203706 A145181 A221353

Adjacent sequences:  A057631 A057632 A057633 * A057635 A057636 A057637

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Oct 10 2000

EXTENSIONS

More terms from Jens Kruse Andersen, May 28 2006

a(17) from Giovanni Resta, Aug 04 2013

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 January 28 13:05 EST 2020. Contains 331321 sequences. (Running on oeis4.)