login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A178082 Numbers k for which 5*k-4, 5*k-2, 5*k+2, and 5*k+4 are primes. 1
3, 21, 39, 165, 297, 375, 417, 651, 693, 1131, 1887, 2601, 3129, 3147, 3213, 3609, 3783, 3885, 4203, 4455, 5061, 6345, 6969, 8757, 10269, 11067, 12597, 13443, 13899, 14445, 15453, 15939, 16209, 16545, 17763, 19569, 19827, 20223, 21969, 23307 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = A173037(n+1)/5.
EXAMPLE
The associated prime quadruplets start as:
. 11, 13, 17, 19; (for n = 3)
. 101, 103, 107, 109; (for n = 21)
. 191, 193, 197, 199; (for n = 39)
. 821, 823, 827, 829;
. 1481, 1483, 1487, 1489;
. 1871, 1873, 1877, 1879;
. 2081, 2083, 2087, 2089;
. 3251, 3253, 3257, 3259;
. 3461, 3463, 3467, 3469;
. 5651, 5653, 5657, 5659;
. 9431, 9433, 9437, 9439;
. 13001, 13003, 13007, 13009;
. 15641, 15643, 15647, 15649;
. 15731, 15733, 15737, 15739;
. 16061, 16063, 16067, 16069;
. 18041, 18043, 18047, 18049;
. 18911, 18913, 18917, 18919;
. 19421, 19423, 19427, 19429.
MATHEMATICA
Flatten[Table[If[PrimeQ[5*n + 2] && PrimeQ[5*n - 2] && PrimeQ[5*n + 4] && PrimeQ[5*n - 4], n, {}], {n, 0, 10000}]]
Select[Range[25000], AllTrue[5#+{4, 2, -2, -4}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 03 2018 *)
PROG
(Magma) [n: n in [0..1000]| IsPrime(5*n - 4) and IsPrime(5*n - 2) and IsPrime(5*n + 2) and IsPrime(5*n + 4)]; Vincenzo Librandi, Nov 30 2010
CROSSREFS
Sequence in context: A227241 A076169 A298035 * A056387 A056377 A146712
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, May 19 2010
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 12 16:06 EDT 2024. Contains 374251 sequences. (Running on oeis4.)