

A290283


Primes p such that A215458(p) is prime.


0



3, 5, 7, 11, 17, 19, 23, 101, 107, 109, 113, 163, 283, 311, 331, 347, 359, 701, 1153, 1597, 1621, 2063, 2437, 2909, 3319, 6011, 12829, 46147, 46471, 74219, 112297, 128411, 178693, 223759, 268841, 407821, 526763, 925391, 927763
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Primes p such that (2^p  (1/2  (i * sqrt(7))/2)^p  (1/2 + (i * sqrt(7))/2)^p + 1)/2 is prime.
It is conjectured that there are infinitely many terms.


LINKS



EXAMPLE



MAPLE

h := proc(n) option remember; `if`(n=0, 2, `if`(n=1, 1, h(n1)2*h(n2))) end:
select(n>isprime((2^nh(n)+1)/2), select(isprime, [$1..1000])); # Peter Luschny, Jul 26 2017


MATHEMATICA

Function[s, Keys@ KeySelect[s, AllTrue[{#, Lookup[s, #]}, PrimeQ] &]]@ MapIndexed[First[#2]  1 > #1 &, LinearRecurrence[{4, 7, 8, 4}, {0, 1, 4, 7}, 7000]] (* Michael De Vlieger, Jul 26 2017 *)


PROG

(PARI) isprime(([0, 1, 0, 0; 0, 0, 1, 0; 0, 0, 0, 1; 4, 8, 7, 4]^n*[0; 1; 4; 7])[1, 1])


CROSSREFS



KEYWORD

nonn,more


AUTHOR



STATUS

approved



