OFFSET
1,1
COMMENTS
The computations were done without any assumptions on the form of d.
LINKS
Sameen Ahmed Khan, Table of n, a(n) for n = 1..210
Sameen Ahmed Khan, Primes in Geometric-Arithmetic Progression, arXiv preprint arXiv:1203.2083 [math.NT], 2012. - From N. J. A. Sloane, Sep 15 2012
EXAMPLE
d = 2523780 then {11 + j*d}, j = 0 to 7, is {11, 2523791, 5047571, 7571351, 10095131, 12618911, 15142691, 17666471} which is 8 primes in arithmetic progression.
MATHEMATICA
a = 11; t = {}; Do[If[PrimeQ[{a, a + d, a + 2*d, a + 3*d, a + 4*d, a + 5*d, a + 6*d, a + 7*d}] == {True, True, True, True, True, True, True, True},
AppendTo[t, d]], {d, 0, 200000000}]; t
Select[Range[117640000], AllTrue[11+#*Range[0, 7], PrimeQ]&] (* Harvey P. Dale, Dec 31 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Sameen Ahmed Khan, Feb 03 2012
STATUS
approved