A209901 7^p - 6^p - 2 with p = prime(n).

11, 125, 9029, 543605, 1614529685, 83828316389, 215703854542469, 10789535445362645, 26579017117027313525, 3183060102526390833854309, 156448938516521406467644085, 18500229372226631089176131976869, 44487435359130133495783012898708549

Offset

1,1

Comments

After 11 and 9029, there are no prime values of a(n) through 7^109 - 6^109 - 2.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..100

Formula

a(n) = A016169(A000040(n)) - 2 = A204768(n) - 1 = A000420(A000040(n)) - A000400(A000040(n)) - 2.

Example

543605 is in the sequence because 543605 = 7^7 - 6^7 - 2, and 7 is prime.

Mathematica

Table[7^p - 6^p - 2, {p, Prime[Range[20]]}] (* T. D. Noe, Mar 15 2012 *)

Prog

(PARI) forprime(p=2, 100, print1(7^p-6^p-2", ")) \\ Charles R Greathouse IV, Mar 15 2012

Crossrefs

Cf. A000040, A000400, A000420, A016169, A204768.

Sequence in context: A163310 A240335 A076483 * A285056 A015597 A296732

Adjacent sequences: A209898 A209899 A209900 * A209902 A209903 A209904

Keyword

nonn,easy,less

Author

Jonathan Vos Post, Mar 14 2012

Status

approved