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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A246178 Expansion of 1/(1 - 3*x + x^2)^3. 0
1, 9, 51, 234, 951, 3573, 12707, 43398, 143682, 464148, 1469778, 4578102, 14063653, 42695127, 128301453, 382144446, 1129360689, 3314619171, 9668400839, 28045947996, 80949547380, 232589050920, 665532883380, 1897176603420, 5389368930505, 15260830474869, 43085718922071, 121310066722194, 340684392838971, 954497114903169 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..29.

Index entries for linear recurrences with constant coefficients, signature (9,-30,45,-30,9,-1).

FORMULA

a(n) = (2*(25 + 39*n + 20*n^2)*F(2*n+1) + (38 + 51*n + 25*n^2)*F(2*n))/50, where F = A000045. - Emanuele Munarini, Mar 08 2018

MAPLE

S := series(1/(1-3*x+x^2)^3, x = 0, 30): seq(coeff(S, x, j), j = 0 .. 30);

MATHEMATICA

Table[(2 (25 + 39 n + 20 n^2) Fibonacci[2n+1] + (38 + 51 n + 25 n^2) Fibonacci[2n])/50, {n, 0, 24}] (* Emanuele Munarini, Mar 08 2018 *)

PROG

(Maxima) makelist(((38+51*n+25*n^2)*fib(2*n)+2*(25+39*n+20*n^2)*fib(1+2*n))/50, n, 0, 30); /* Emanuele Munarini, Mar 08 2018 */

(PARI) x='x+O('x^99); Vec(1/(1-3*x+x^2)^3) \\ Altug Alkan, Mar 08 2018

CROSSREFS

Cf. A001906, A001871.

Sequence in context: A005746 A220236 A061178 * A213164 A278135 A097789

Adjacent sequences:  A246175 A246176 A246177 * A246179 A246180 A246181

KEYWORD

nonn,easy

AUTHOR

Emeric Deutsch, Aug 23 2014

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 October 15 09:22 EDT 2019. Contains 328026 sequences. (Running on oeis4.)