

A123678


Numbers n such that Lucas(prime(prime(n))) is prime, where Lucas(k) = A000032(k).


3



2, 3, 4, 5, 6, 20, 30, 117, 136, 1616, 5313
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OFFSET

1,1


COMMENTS

Indices of prime Lucas numbers are listed in A001606.
Numbers n such that Lucas(prime(n)) is prime are listed in A120561.
Primes in A120561 are listed in A123677(n) = prime(a(n)).


LINKS

Table of n, a(n) for n=1..11.


FORMULA

a(n) = pi(A123677(n)).
a(n) = pi(pi(A277290(n))).  Bobby Jacobs, Oct 30 2016


CROSSREFS

Cf. A000032, A123677, A120561, A001606, A277290.
Cf. A119984, A122534 (Numbers n such that Fibonacci(prime(prime(n))) is prime).
Sequence in context: A031015 A329581 A024639 * A208450 A037333 A183529
Adjacent sequences: A123675 A123676 A123677 * A123679 A123680 A123681


KEYWORD

hard,more,nonn


AUTHOR

Alexander Adamchuk, Oct 05 2006


EXTENSIONS

5313 found by Henri Lifchitz, from Jens Kruse Andersen, Jul 24 2014


STATUS

approved



