OFFSET
1,1
COMMENTS
The terms n = 1..26 are prime. This is the longest and largest sequence of primes in arithmetic progression, a(26)=427126874628779911, known as of August 10, 2015.
LINKS
Jens Kruse Andersen, All known AP24 to AP26.
Wikipedia, Largest known primes in AP.
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 161004359399459161 + (n-1)*47715109*A002110(9).
G.f.: x*(161004359399459161 - 150359458790286331*x)/(1 - x)^2. [Bruno Berselli, Aug 23 2015]
EXAMPLE
a(26) = 161004359399459161 + 25*10644900609172830 = 427126874628779911 is prime.
MATHEMATICA
Table[161004359399459161 + (n - 1) 10644900609172830, {n, 1, 20}] (* Bruno Berselli, Aug 23 2015 *)
PROG
(Magma) [161004359399459161+(n-1)*10644900609172830: n in [1..20]]; // Bruno Berselli, Aug 23 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Marco Ripà, Aug 10 2015
STATUS
approved