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%I #25 Mar 03 2022 11:45:33
%S 1,1,1,1,2,3,7,11,28,120,197,892,2479,4148,11687,56010,271913,461529,
%T 2270882,6599404,11263855,56250108,164879269,830987861,7231032935,
%U 21386730355,36802336319,109099442316,187943217386
%N a(n) = c(prime(n))/prime(n), where c = Perrin sequence A001608 (starting 0,2,3,...) and prime(n) is the n-th prime.
%H Seiichi Manyama, <a href="/A014981/b014981.txt">Table of n, a(n) for n = 1..1000</a> (terms 1..200 from T. D. Noe)
%H Ondrej Such, <a href="https://www.jstor.org/stable/2974627">An Insufficient Condition for Primality, Problem 10268</a>, Amer. Math. Monthly, Vol. 103, No. 10 (1996), p. 911.
%o (PARI) c(n) = polsym(x^3-x-1,n)[n+1]; \\ A001608
%o a(n) = my(p=prime(n)); c(p)/p; \\ _Michel Marcus_, Mar 03 2022
%Y See A001608, the main entry for the Perrin sequence.
%Y Cf. A000040, A052338, A064723.
%K nonn,easy,nice
%O 1,5
%A _Clark Kimberling_, _Robert G. Wilson v_
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