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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A090839 Numbers n such that 6*n+1, 6*n+7, 6*n+13, 6*n+19 are consecutive primes. 11
 290, 550, 850, 1060, 2650, 3035, 3245, 5015, 5105, 8935, 10615, 11890, 12925, 13485, 13905, 14850, 15215, 15985, 17560, 17600, 18105, 19925, 20135, 21780, 23510, 24040, 25490, 28830, 31145, 34365, 36355, 38140, 38370, 42025, 43845, 46820, 47575, 48745, 49130, 50495, 53350 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are == 0 (mod 5). - Robert G. Wilson v, Dec 12 2017 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE 6*290 + 1 = 1741, 6*290 + 7 = 1747, 6*290 + 13 = 1753, 6*290 + 19 = 1759 and 1741, 1747, 1753, 1759 are consecutive primes, so 290 is a term. MAPLE P:=proc(n) if isprime(6*n+1) and isprime(6*n+7) and isprime(6*n+13) and isprime(6*n+19) and not isprime(6*n+5) and not isprime(6*n+11) and not isprime(6*n+17) then n; fi; end: seq(P(i), i=1..10^5); # Paolo P. Lava, Dec 07 2017 MATHEMATICA Block[{nn = 50500, s}, s = Select[Prime@ Range@ PrimePi[6 (nn + 3) - 1], Divisible[(# + 1), 6] &]; Select[Range@ nn, And[AllTrue[#, PrimeQ], Count[s, q_ /; First[#] < q < Last@ #] == 0] &@ Map[6 # + 1 &, # + Range[0, 3]] &]] (* Michael De Vlieger, Dec 06 2017 *) fQ[n_] := Block[{p = {6n +1, 6n +7, 6n +13, 6n +19}}, Union@ PrimeQ@ p == {True} && NextPrime[6n +1, 3] == 6n +19]; Select[5 Range@ 10100, fQ] (* Robert G. Wilson v, Dec 12 2017 *) PROG (PARI) isok(n) = my(p, q, r); isprime(p=6*n+1) && ((q=6*n+7) == nextprime(p+1)) && ((r=6*n+13) == nextprime(q+1)) && (6*n+19 == nextprime(r+1)); \\ Michel Marcus, Sep 20 2019 CROSSREFS Cf. A033451, A090832, A090833, A090834, A090835, A090836, A090837, A090838. Sequence in context: A075421 A332229 A296055 * A158255 A295483 A075299 Adjacent sequences:  A090836 A090837 A090838 * A090840 A090841 A090842 KEYWORD easy,nonn,changed AUTHOR Pierre CAMI, Dec 09 2003 EXTENSIONS Missing term 5105 and more terms from Michel Marcus, Sep 20 2019 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 April 11 03:12 EDT 2021. Contains 342886 sequences. (Running on oeis4.)