login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

A157456
Expansion of x * (1 - x) / (1 - 16*x + x^2).
21
1, 15, 239, 3809, 60705, 967471, 15418831, 245733825, 3916322369, 62415424079, 994730462895, 15853271982241, 252657621252961, 4026668668065135, 64174041067789199, 1022757988416562049, 16299953773597203585, 259776502389138695311, 4140124084452621921391
OFFSET
1,2
COMMENTS
Positive values of x (or y) satisfying x^2 - 16xy + y^2 + 14 = 0. - Colin Barker, Feb 11 2014
LINKS
J.-C. Novelli, J.-Y. Thibon, Hopf Algebras of m-permutations,(m+1)-ary trees, and m-parking functions, arXiv preprint arXiv:1403.5962 [math.CO], 2014.
FORMULA
G.f.: x*(1-x) / ( 1-16*x+x^2 ). - R. J. Mathar, Oct 31 2011
a(n) = 16*a(n-1)-a(n-2). - Colin Barker, Feb 11 2014
a(n) = (1/18)*(9-sqrt(63))*(1+(8+sqrt(63))^(2*n-1))/(8+sqrt(63))^(n-1). [Bruno Berselli, Feb 25 2014]
a(n) = sqrt(2+(8-3*sqrt(7))^(1+2*n)+(8+3*sqrt(7))^(1+2*n))/(3*sqrt(2)). - Gerry Martens, Jun 06 2015
a(n) = A077412(n-1) - A077412(n-2). - R. J. Mathar, Feb 05 2020
MAPLE
f:= gfun:-rectoproc({a(n)=16*a(n-1)-a(n-2), a(1)=1, a(2)=15}, a(n), remember):
map(f, [$1..30]); # Robert Israel, Jul 07 2015
MATHEMATICA
CoefficientList[Series[(1 - x)/(1 - 16 x + x^2), {x, 0, 40}], x] (* Vincenzo Librandi, Feb 12 2014 *)
LinearRecurrence[{16, -1}, {1, 15}, 20] (* Harvey P. Dale, Sep 17 2019 *)
PROG
(Magma) I:=[1, 15]; [n le 2 select I[n] else 16*Self(n-1)-Self(n-2): n in [1..30]]; // Vincenzo Librandi, Feb 12 2014
CROSSREFS
Cf. A159678.
Cf. similar sequences listed in A238379.
Sequence in context: A209118 A093745 A071811 * A343527 A097262 A158557
KEYWORD
nonn,easy
AUTHOR
Paul Weisenhorn, Mar 01 2009
EXTENSIONS
New name (using the g.f. by R. J. Mathar) from Joerg Arndt, Jun 06 2015
STATUS
approved

pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy