A204768 7^p - 6^p - 1, with p = prime(n).

12, 126, 9030, 543606, 1614529686, 83828316390, 215703854542470, 10789535445362646, 26579017117027313526, 3183060102526390833854310, 156448938516521406467644086, 18500229372226631089176131976870

Offset: 1

Author

Vincenzo Librandi, Mar 07 2012

Keywords

• nonn

Comments

For n>2 all terms are divisible by 1806 = 2*3*7*43.

Links

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

Crossrefs

Cf. A016169.

Programs

Magma

[(7^p-6^p-1): p in PrimesUpTo(100)];

Mathematica

Table[(7^Prime[n] - 6^Prime[n] - 1), {n, 1, 20}] (* Vincenzo Librandi, May 04 2014 *)
7^#-6^#-1&/@Prime[Range[20]] (* Harvey P. Dale, Aug 17 2024 *)