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A190354 Primes p such that p,q,r,s are consecutive primes and 2p+9, 2q+9, 2r+9, 2s+9 are also primes. 1
887, 907, 4211, 6569, 8447, 23339, 23357, 30809, 33427, 33937, 38839, 57529, 57557, 57859, 70271, 77621, 77641, 77647, 77659, 80747, 86587, 87691, 109537, 115769, 116041, 117251, 160681, 192781, 207797, 217387, 228257, 228281, 232457, 244339 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The smallest in a group of four consecutive primes in A023207. - R. J. Mathar, Jun 02 2011

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

MAPLE

isA023207 := proc(n) isprime(n) and isprime(2*n+9) ; end proc:

isA190354 := proc(n) local q, r, s ; if isprime(n) then q := nextprime(n) ; r := nextprime(q) ; s := nextprime(r) ; isA023207(n) and isA023207(q) and isA023207(r) and isA023207(s) ; else return false; end if; end proc:

for i from 1 do p := ithprime(i) ; if isA190354(p) then print(p) ; end if; end do: # R. J. Mathar, Jun 02 2011

MATHEMATICA

p2Q[n_]:=And@@PrimeQ[2#+9&/@n]; Transpose[Select[Partition[Prime[ Range[22000]], 4, 1], p2Q]][[1]] (* Harvey P. Dale, Jun 10 2011 *)

PROG

(PARI) old(p, k)=while(k--, p=precprime(p-1)); p; k=0; forprime(p=2, 1e6, if(isprime(p+p+9), if(k++>3, print1(old(p, 4)", ")), k=0))

CROSSREFS

Sequence in context: A031794 A020393 A103811 * A164513 A031938 A165504

Adjacent sequences:  A190351 A190352 A190353 * A190355 A190356 A190357

KEYWORD

nonn

AUTHOR

Pierre CAMI, May 09 2011

STATUS

approved

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Last modified January 23 06:56 EST 2022. Contains 350504 sequences. (Running on oeis4.)