A253210 a(n) = 7^n + 6.

7, 13, 55, 349, 2407, 16813, 117655, 823549, 5764807, 40353613, 282475255, 1977326749, 13841287207, 96889010413, 678223072855, 4747561509949, 33232930569607, 232630513987213, 1628413597910455, 11398895185373149, 79792266297612007, 558545864083284013

Offset: 0

Author

Vincenzo Librandi, Dec 29 2014

Keywords

• nonn
• easy

Comments

Subsequence of A226819.

Links

• Index entries for linear recurrences with constant coefficients, signature (8,-7).

Crossrefs

Cf. similar sequences listed in A253208.

Cf. A164783, A226819.

Programs

Magma

[7^n+6: n in [0..30]];

Mathematica

Table[7^n + 6, {n, 0, 30}]

Formula

G.f.: (7 - 43*x) / ((1 - x)*(1 - 7*x)).

a(n) = 8*a(n-1) - 7*a(n-2) for n>1.