This site is supported by donations to The OEIS Foundation. Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A117844 Primes generated from a gamma function based formula: very large primes from factorial level numbers like the Euclid n!+1 type of prime. 0

%I

%S 3,19,6652799,3779,831599,108972863999,32432399,538583682060103679999,

%T 115783667999,79196028911999,113425723441857835007999999,

%U 9899503613999,10098444038626943999999,8960776752100485056195299206758399999999

%N Primes generated from a gamma function based formula: very large primes from factorial level numbers like the Euclid n!+1 type of prime.

%C Gives 31% primes from ten levels the last one with 39 powers of ten. alength = Length[a]*(Length[a] - 1)/2=45 N[Length[b]/alength]=0.311111 (*Decimal digit length*) Floor[Log[b]/Log] {0, 1, 6, 3, 5, 11, 7, 20, 11, 13, 26, 12, 22, 39}

%F f[n_, m_] = FullSimplify[((4/3)*Gamma[2*(n + m)]/(2^m*2^(2*(n - m))))] - 1 a(n) = If[PrimeQ[f[i,j]]=True,f[i,j]]

%t f[n_, m_] = FullSimplify[((4/3)*Gamma[2*(n + m)]/(2^m*2^(2*(n - m))))] - 1 a = Table[Table[If[PrimeQ[f[n, m]], f[n, m], {}], {m, 1, n}], {n, 1, 10}] b = Flatten[a]

%K nonn,uned

%O 0,1

%A _Roger L. Bagula_, Apr 30 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 11 02:16 EST 2019. Contains 329910 sequences. (Running on oeis4.)