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A256491 a(n) = prime(prime(n) + n - 2). 1

%I

%S 2,5,13,23,43,59,79,97,113,157,173,211,239,257,281,331,373,389,433,

%T 461,479,523,569,607,659,691,719,751,769,811,911,947,997,1019,1091,

%U 1103,1163,1217,1249,1297,1361,1381,1459,1483,1511,1543,1619,1723,1759,1787,1831

%N a(n) = prime(prime(n) + n - 2).

%C All terms are prime.

%F a(n) = A256464(prime(n)).

%e a(3) = prime(prime(3) + 3 - 2) = prime(5 + 3 - 2) = prime(6) = 13.

%e a(4) = prime(prime(4) + 4 - 2) = prime(7 + 4 - 2) = prime(9) = 23.

%e a(5) = prime(prime(5) + 4 - 2) = prime(11 + 4 - 2) = prime(13) = 43.

%t Table[Prime[Prime[n] + n - 2], {n, 51}] (* _Jon Maiga_, Nov 20 2018 *)

%o (PARI) a(n) = {i = prime(n); stop = 0; while (! stop, vab = vector(i, k, sigma(k)/k); w = vecsort(vab, , 1); pos = posv(n, w); if (pos == n, stop=1, i++);); i;}

%Y Cf. A256464.

%K nonn

%O 1,1

%A _Michel Marcus_, Mar 30 2015

%E Name clarified by _Alonso del Arte_, Nov 20 2018, was "A256464(prime(n))."

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Last modified February 6 18:02 EST 2023. Contains 360111 sequences. (Running on oeis4.)