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%I #7 Jul 25 2015 01:12:47
%S 1,3,10,39,196,1175,8226,65807,592262,5922619,65148810,781785719,
%T 10163214348,142285000871,2134275013064,34148400209023,
%U 580522803553392,10449410463961055,198538798815260046,3970775976305200919
%N a(1) = 1; for n>1, a(n) = n*a(n-1) + 1 if n is a prime else a(n) = n*a(n-1) - 1.
%t a[1] = 1; a[n_] := a[n] = (p = n*a[n - 1] + 1; If[ PrimeQ[n], p, p - 2]); Table[ a[n], {n, 20}] (* _Robert G. Wilson v_, Apr 08 2004 *)
%Y Cf. A093464.
%K nonn
%O 1,2
%A _Amarnath Murthy_, Apr 05 2004
%E More terms from _Robert G. Wilson v_, Apr 08 2004