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a(n) = A089026(n) - 1.
1

%I #14 Oct 13 2018 09:25:42

%S 0,1,2,0,4,0,6,0,0,0,10,0,12,0,0,0,16,0,18,0,0,0,22,0,0,0,0,0,28,0,30,

%T 0,0,0,0,0,36,0,0,0,40,0,42,0,0,0,46,0,0,0,0,0,52,0,0,0,0,0,58,0,60,0,

%U 0,0,0,0,66,0,0,0,70,0,72,0,0,0,0,0,78,0,0,0,82,0,0,0,0,0,88,0,0,0,0,0,0

%N a(n) = A089026(n) - 1.

%C Same as A061006 except for a(4) = 0 (Wilson's Theorem). - _Georg Fischer_, Oct 12 2018

%F a(n) = (n-1) * A010051(n). - _Wesley Ivan Hurt_, Oct 12 2018

%o (PARI) a(n) = if (isprime(n), n-1, 0); \\ _Michel Marcus_, Oct 12 2018

%Y Cf. A010051, A061006, A089026.

%Y Cf. A119690. - _R. J. Mathar_, Oct 16 2009

%K nonn

%O 1,3

%A _Mats Granvik_, Oct 10 2009