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!)
A206045 Numbers d such that 11 + j*d is prime for j = 0 to 10. 15
1536160080, 4911773580, 25104552900, 77375139660, 83516678490, 100070721660, 150365447400, 300035001630, 318652145070, 369822103350, 377344636200, 511688932650, 580028072610, 638663371710, 701534299830, 745828915650, 776625236100, 883476548850, 925639075620, 956863233690 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Original name: Values of the difference d for 11 primes in arithmetic progression with the minimal start sequence {11 + j*d}, j = 0 to 10.
The computations were done without any assumptions on the form of d. 21st term is greater than 10^12.
All terms are multiples of 210=2*3*5*7. - Zak Seidov, May 16 2015
Equivalently, integers d such that the longest possible arithmetic progression (AP) of primes with common difference d has exactly 11 elements (see example). These 11 elements are not necessarily consecutive primes. In fact, here, for each term d, there exists only one such AP of primes, and this one always starts with A342309(d) = 11, so this unique AP is (11, 11+d, 11+2d, 11+3d, 11+4d, 11+5d, 11+6d, 11+7d, 11+8d, 11+9d, 11+10d). - Bernard Schott, Mar 08 2023
LINKS
Diophante, A1880. NP en PA (prime numbers in arithmetic progression) (in French).
Sameen Ahmed Khan, Primes in Geometric-Arithmetic Progression, arXiv preprint arXiv:1203.2083 [math.NT], 2012.
FORMULA
m is a term iff A123556(m) = 11. - Bernard Schott, Mar 08 2023
EXAMPLE
d = 4911773580 then {11, 4911773591, 9823547171, 14735320751, 19647094331, 24558867911, 29470641491, 34382415071, 39294188651, 44205962231, 49117735811} which is 11 primes in arithmetic progression.
MATHEMATICA
a = 11; Do[If[PrimeQ[{a, a + d, a + 2*d, a + 3*d, a + 4*d, a + 5*d, a + 6*d, a + 7*d, a + 8*d, a + 9*d, a + 10*d}] == {True, True, True, True, True, True, True, True, True, True, True}, Print[d]], {d, 210, 10^12, 210}] (* corrected by Zak Seidov, May 16 2015 *)
Select[Range[210, 10^12, 210], AllTrue[Range[0, 10]#+11, PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 28 2016 *)
PROG
(PARI) is(n)=for(j=1, 10, if(!isprime(j*n+11), return(0))); 1 \\ Charles R Greathouse IV, May 18 2015
CROSSREFS
Common differences for longest possible APs of primes with exactly k elements: A007921 (k=1), A359408 (k=2), A206037 (k=3), A359409 (k=4), A206039 (k=5), A359410 (k=6), A206041 (k=7), A360146 (k=10), this sequence (k=11).
Sequence in context: A157822 A034616 A084551 * A276820 A273815 A258885
KEYWORD
nonn
AUTHOR
Sameen Ahmed Khan, Feb 03 2012
EXTENSIONS
New name from Charles R Greathouse IV, May 18 2015
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 18 18:59 EDT 2024. Contains 374388 sequences. (Running on oeis4.)