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%I #21 Dec 31 2018 16:12:39
%S 0,0,4,102,329890,36846276,1230752346352,336967037143578,
%T 48869596859895986086,10513391193507374500051862068,
%U 8556543864909388988268015483870,10053873697024357228864849950022572972972
%N a(n) = ((p-1)!/p) - ((p-1)*(p-1)!/p!), where p is the n-th prime.
%C Related to Wilson's Theorem. Let p be a prime number and write 1/p - (p-1)/p! = x/(p-1)!. Then x = (p-1)!/p - (p-1)*(p-1)!/p! = (p-1)!/p - (p-1)/p.
%C Also, a(n) = floor((p-1)!/p). [_Bruno Berselli_, May 31 2013]
%C If b(1)=1, and b(m) = ((m-1)^2 / m) *(b(m-1)+(m-3)/(m-1)) for m>1, then a(n) are the terms of b(m) for m prime. [_Pedro Caceres_, Dec 30 2018]
%e Prime(4)=7 so a(4) = 6!/7 - 6*6!/7! = 102
%t A091330[n_] := Block[{p = Prime[n]}, ((p - 1)!/p) - ((p - 1)*(p - 1)!/p!)] (* _Robert G. Wilson v_, Mar 02 2004 *)
%Y Cf. A007619.
%K nonn,easy
%O 1,3
%A _Russell Easterly_, Mar 01 2004
%E More terms from _Robert G. Wilson v_ and _Ray Chandler_, Mar 02 2004
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