login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A048479 a(n) = T(7,n), array T given by A048472. 1
1, 9, 33, 97, 257, 641, 1537, 3585, 8193, 18433, 40961, 90113, 196609, 425985, 917505, 1966081, 4194305, 8912897, 18874369, 39845889, 83886081, 176160769, 369098753, 771751937, 1610612737, 3355443201, 6979321857, 14495514625, 30064771073, 62277025793 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

n-th difference of a(n), a(n-1), ..., a(0) is (8, 16, 24, ...).

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (5,-8,4).

FORMULA

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

a(n) = 5*a(n-1)-8*a(n-2)+4*a(n-3) for n>2. G.f.: (1+4*x-4*x^2) / ((1-x)*(1-2*x)^2). - Colin Barker, Feb 18 2016

a(n) = Sum_{k=0..n+2} Sum_{i=0..n+2} C(n+1,i) - C(k,i). - Wesley Ivan Hurt, Sep 21 2017

MATHEMATICA

Table[8 n*2^(n - 1) + 1, {n, 0, 29}] (* or *)

CoefficientList[Series[(1 + 4 x - 4 x^2)/((1 - x) (1 - 2 x)^2), {x, 0, 29}], x] (* Michael De Vlieger, Sep 22 2017 *)

PROG

(MAGMA) [8*n * 2^(n-1) + 1: n in [0..30]]; // Vincenzo Librandi, Sep 23 2011

(PARI) Vec((1+4*x-4*x^2)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Colin Barker, Feb 18 2016

CROSSREFS

Cf. A048472.

Sequence in context: A201024 A228170 A112888 * A031880 A231765 A220165

Adjacent sequences:  A048476 A048477 A048478 * A048480 A048481 A048482

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified January 24 03:35 EST 2018. Contains 298115 sequences.