A340770 Indices k of prime numbers such that prime(k)-2 and prime(k)^2-2 are both prime numbers.

3, 4, 6, 8, 14, 18, 27, 34, 65, 82, 99, 141, 172, 177, 191, 202, 216, 226, 319, 333, 337, 445, 470, 476, 496, 552, 559, 564, 578, 602, 637, 672, 829, 850, 863, 871, 949, 1005, 1065, 1075, 1190, 1199, 1231, 1239, 1306, 1329, 1446, 1450, 1529, 1619, 1635, 1643

Offset

1,1

Comments

This sequence is a subsequence of A107770.

Links

François Marques, Table of n, a(n) for n = 1..10000

Example

6 is in the sequence since prime(6)=13 and 13-2=11 and 13^2-2=167 are both prime numbers.

Prog

(PARI) lista(n) = {my(l=List, k=1); while(#l<n, k++; if(isprime(prime(k)-2) && isprime(prime(k)^2-2), listput(l, k))); return(l)};

Crossrefs

Cf. A107770, A292201.

Sequence in context: A356081 A004713 A050475 * A242870 A025073 A325432

Adjacent sequences: A340767 A340768 A340769 * A340771 A340772 A340773

Keyword

nonn,easy

Author

François Marques, Jan 20 2021

Status

approved