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

Author

Jonathan Vos Post, Mar 14 2012

Keywords

• nonn
• easy
• less

Comments

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

Examples

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

Links

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

Crossrefs

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

Programs

Mathematica

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

PARI

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

Formula

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