OFFSET
0,2
COMMENTS
If a(n) is composite then a(n)>10^(2n)+2*10^n. Conjecture: All terms are noncomposite numbers.
(10^4)!+44159 is a probable prime. - Jason Yuen, May 20 2024
FORMULA
a(n) = A033932(10^n). - Jason Yuen, May 20 2024
EXAMPLE
a(3)=1283 because (10^3)!+1283 is prime and for 0<m<1283 1000!+m is
composite.
MATHEMATICA
a[n_] := (For[m = 1, ! PrimeQ[(10^n)! + m], m++ ]; m); Do[Print[a[n]], {n, 0, 3}]
sp[n_]:=Module[{c=(10^n)!}, NextPrime[c]-c]; Array[sp, 4, 0] (* Harvey P. Dale, Jul 29 2013 *)
CROSSREFS
KEYWORD
more,nonn,hard
AUTHOR
Farideh Firoozbakht, Jul 10 2005
EXTENSIONS
a(4) from Jason Yuen, May 20 2024
STATUS
approved