login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A099359 a(n) = (2^n + 1)^3 - 2. 3
6, 25, 123, 727, 4911, 35935, 274623, 2146687, 16974591, 135005695, 1076890623, 8602523647, 68769820671, 549957165055, 4398851866623, 35187593412607, 281487861809151, 2251851353686015, 18014604668698623, 144116012711149567, 1152924803144876031 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Eric Weisstein's World of Mathematics, Integer sequence primes.

Index entries for linear recurrences with constant coefficients, signature (15,-70,120,-64).

FORMULA

From Colin Barker, Jan 10 2017: (Start)

a(n) = (3*2^n + 3*4^n + 8^n - 1).

a(n) = 15*a(n-1) - 70*a(n-2) + 120*a(n-3) - 64*a(n-4) for n>3.

G.f.: (6 - 65*x + 168*x^2 - 88*x^3) / ((1 - x)*(1 - 2*x)*(1 - 4*x)*(1 - 8*x)).

(End)

EXAMPLE

(2^1 + 1)^3 - 2 = 25.

MATHEMATICA

Table[(2^n + 1)^3 - 2, {n, 19}] (* Robert G. Wilson v, Nov 23 2004 *)

PROG

(PARI) a(n)=(2^n+1)^3-2 \\ Charles R Greathouse IV, Feb 19 2016

(PARI) Vec((6 - 65*x + 168*x^2 - 88*x^3) / ((1 - x)*(1 - 2*x)*(1 - 4*x)*(1 - 8*x)) + O(x^30)) \\ Colin Barker, Jan 10 2017

CROSSREFS

Cf. A098878.

Sequence in context: A298700 A215763 A153481 * A073967 A188207 A275541

Adjacent sequences:  A099356 A099357 A099358 * A099360 A099361 A099362

KEYWORD

nonn,easy

AUTHOR

Parthasarathy Nambi, Nov 16 2004

EXTENSIONS

More terms from Robert G. Wilson v, Nov 23 2004

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 21 02:10 EDT 2021. Contains 343143 sequences. (Running on oeis4.)