A257272 a(n) = 2^(n-1)*(2^n+7).

4, 9, 22, 60, 184, 624, 2272, 8640, 33664, 132864, 527872, 2104320, 8402944, 33583104, 134275072, 536985600, 2147713024, 8590393344, 34360655872, 137440788480, 549759483904, 2199030595584, 8796107702272, 35184401448960, 140737547075584, 562950070861824, 2251800048566272, 9007199724503040

Offset: 0

Author

M. F. Hasler, Apr 27 2015

Keywords

• nonn
• easy

Comments

For n in A057195, a(n) is of deficiency 8, i.e., in A125247.

Also, the third column (k=2) of the table given in A181444.

Links

• Colin Barker, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (6,-8).

Crossrefs

Cf. A000079, A007582, A028403, A256873, A257273, A256871.

Cf. A168415, A057195, A104066, A125247.

Programs

Magma

[2^(n-1)*(2^n+7): n in [0..25]]; // Vincenzo Librandi, Apr 27 2015

Mathematica

Table[2^(n - 1) (2^n + 7), {n, 0, 30}] (* Bruno Berselli, Apr 27 2015 *)
CoefficientList[Series[(4 - 15 x)/((1 - 4 x) (1 - 2 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Apr 27 2015 *)

PARI

a(n)=2^(n-1)*(2^n+7)

PARI

Vec((4-15*x)/((1-4*x)*(1-2*x)) + O(x^100)) \\ Colin Barker, Apr 27 2015

Formula

a(n) = 2^(n-1)*A168415(n).

n in A057195 <=> A168415(n) in A104066 <=> a(n) in A125247.

G.f.: (4-15*x)/((1-4*x)*(1-2*x)). - Vincenzo Librandi, Apr 27 2015