A297623 Numbers k such that Lucas(k) - prime(k) is a prime.

6, 9, 18, 33, 51, 54, 57, 189, 6948, 28617, 162864, 173682, 216870, 496533

Offset

1,1

Comments

a(15) > 5*10^5. - Robert Price, Feb 17 2018

Links

Table of n, a(n) for n=1..14.

Example

a(1) = 6 because Lucas(6)=18, prime(6)=13 and 18-13=5 is a prime.

Mathematica

Select[Range[10000], PrimeQ[LucasL[#] - Prime[#]]&]

Prog

(Magma) [n: n in [1..5000] | IsPrime(Lucas(n)-NthPrime(n))];

Crossrefs

Cf. A000032, A000040, A050180, A288794.

Sequence in context: A045091 A086955 A270794 * A293283 A078415 A265099

Adjacent sequences: A297620 A297621 A297622 * A297624 A297625 A297626

Keyword

nonn,more

Author

Vincenzo Librandi, Jan 06 2018

Extensions

a(11)-a(14) from Robert Price, Feb 17 2018

Status

approved