A155629 a(n) = 8^n-4^n+1^n.

1, 5, 49, 449, 3841, 31745, 258049, 2080769, 16711681, 133955585, 1072693249, 8585740289, 68702699521, 549688705025, 4397778075649, 35183298347009, 281470681743361, 2251782633816065, 18014329790005249, 144114913197948929

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Index entries for linear recurrences with constant coefficients, signature (13,-44,32).

Formula

G.f.: 1/(1-8*x)-1/(1-4*x)+1/(1-x). E.g.f.: e^(8*x)-e^(4*x)+e^x.

a(n) = 12*a(n-1)-32*a(n-2)+21 with a(0)=1, a(1)=5. - Vincenzo Librandi, Jul 21 2010

Prog

(PARI) a(n)=8^n-4^n+1 \\ Charles R Greathouse IV, Sep 24 2015

Crossrefs

Cf. A155596, A155597, A155598, A155599, A155600, A155601, A155622, A155623, A155624, A155625, A155626, A155627, A155628.

Sequence in context: A351586 A224756 A198969 * A096596 A001079 A146311

Adjacent sequences: A155626 A155627 A155628 * A155630 A155631 A155632

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 30 2009

Status

approved