OFFSET
1,1
COMMENTS
The terms n = 1..24 are prime. This is the longest known sequence of 24 primes in arithmetic progression with minimal end known as of August 10, 2015.
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
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) = 515486946529943 + (n-1)*136831*A002110(9).
G.f.: -x*(484960926034973*x-515486946529943) / (x-1)^2. - Colin Barker, Aug 25 2015
EXAMPLE
a(24) = 515486946529943 + 23*30526020494970 = 1217585417914253 is prime.
MATHEMATICA
Table[515486946529943 + (n - 1) 30526020494970, {n, 1, 20}]
PROG
(Sage) [515486946529943+(n-1)*30526020494970 for n in (1..20)] #
(Magma) [515486946529943+(n-1)*30526020494970: n in [1..20]];
(PARI) Vec(-x*(484960926034973*x-515486946529943)/(x-1)^2 + O(x^40)) \\ Colin Barker, Aug 25 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Marco Ripà, Aug 10 2015
STATUS
approved