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

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A292291 Number of vertices of type B at level n of the hyperbolic Pascal pyramid. 1
0, 0, 0, 3, 12, 36, 99, 264, 696, 1827, 4788, 12540, 32835, 85968, 225072, 589251, 1542684, 4038804, 10573731, 27682392, 72473448, 189737955, 496740420, 1300483308, 3404709507, 8913645216, 23336226144, 61095033219, 159948873516, 418751587332, 1096305888483 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

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

László Németh, Hyperbolic Pascal pyramid, arXiv:1511.0267 [math.CO], 2015 (2nd line of Table 1).

Index entries for linear recurrences with constant coefficients, signature (4,-4,1).

FORMULA

a(n) = 4*a(n-1) - 4*a(n-2) + a(n-3), n >= 4.

G.f.: 3*x^3 / ((1 - x)*(1 - 3*x + x^2)). - Colin Barker, Sep 17 2017

MATHEMATICA

CoefficientList[Series[3*x^3/((1 - x)*(1 - 3*x + x^2)), {x, 0, 30}], x] (* Wesley Ivan Hurt, Sep 17 2017 *)

LinearRecurrence[{4, -4, 1}, {0, 0, 0, 3}, 40] (* Harvey P. Dale, Oct 25 2017 *)

PROG

(PARI) concat(vector(3), Vec(3*x^3 / ((1 - x)*(1 - 3*x + x^2)) + O(x^40))) \\ Colin Barker, Sep 17 2017

CROSSREFS

Cf. A264236.

Sequence in context: A225259 A242526 A167667 * A215919 A027327 A290927

Adjacent sequences:  A292288 A292289 A292290 * A292292 A292293 A292294

KEYWORD

nonn,easy

AUTHOR

Eric M. Schmidt, Sep 13 2017

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 December 18 10:31 EST 2018. Contains 318219 sequences. (Running on oeis4.)