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%I #6 Aug 24 2012 10:50:03
%S 2,3,61,601,1483,631531,12912301,67501394731,622341432613,
%T 10006712616835423333725869390401
%N Primes of the form R(n!!+1)
%H Paolo P. Lava & Giorgio Balzarotti, <a href="/A173915/b173915.txt">Table of n, a(n) for n = 1..11</a>
%e n=7 -> 7!!+1 = 105+1=106 -> R(106)=601 is prime
%p P:=proc(i) local a,b,k,n,v; v:=array(1..10000); for n from 1 by 1 to i do a:=1; k:=doublefactorial(n)+1; while k>0 do v[a]:=k-(trunc(k/10)*10); k:=trunc(k/10); a:=a+1; od; k:=0; for b from a-1 by -1 to 1 do k:=k+v[b]*10^(a-1-b); od; if isprime(k) then print(k); fi; od; end: P(2000);
%Y Cf. A173913, A173914, A173916.
%K nonn
%O 1,1
%A _Paolo P. Lava_ and _Giorgio Balzarotti_, Mar 02 2010
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