cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A138112 a(n)=3a(n-1)-4a(n-2)+2a(n-3)-a(n-4), a(0)=a(1)=a(2)=0, a(3)=1, a(4)=3.

Original entry on oeis.org

0, 0, 0, 1, 3, 5, 5, 0, -13, -34, -55, -55, 0, 144, 377, 610, 610, 0, -1597, -4181, -6765, -6765, 0, 17711, 46368, 75025, 75025, 0, -196418, -514229, -832040, -832040, 0, 2178309, 5702887, 9227465, 9227465, 0, -24157817, -63245986, -102334155, -102334155
Offset: 0

Views

Author

Paul Curtz, May 04 2008

Keywords

Comments

Obeys also the recurrence a(n)=5a(n-1)-10a(n-2)+10a(n-3)-5a(n-4)+2a(n-5), so the sequence is identical to its fifth differences (cf. A135356). a(n) = A138110(0,n): if A138110 is interpreted as an array with five rows, this is the top row.
The first differences are represented by A100334(n-1).
The 2nd differences are represented by A103311(n).
The 3rd differences are essentially represented by -A138003(n-2).
The 4th differences are represented by -A105371(n).
A102312 contains the absolute values of the terms which occur in pairs, for example a(5)=a(6)=5=A102312(1), a(10)=a(11)= -55 = -A102312(2).
Inverse BINOMIAL transform yields two zeros followed by A105384. - R. J. Mathar, Jul 04 2008

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[x^3/(1-3x+4x^2-2x^3+x^4),{x,0,45}],x] (* or *) LinearRecurrence[{3,-4,2,-1},{0,0,0,1},45] (* Harvey P. Dale, Jun 22 2011 *)

Formula

O.g.f.: x^3/(1-3x+4x^2-2x^3+x^4). - R. J. Mathar, Jul 04 2008

Extensions

Edited and extended by R. J. Mathar, Jul 04 2008

A171373 Binomial transform of A171372.

Original entry on oeis.org

1, 6, 16, 36, 76, 152, 292, 552, 1052, 2052, 4104, 8344, 17044, 34664, 69904, 139808, 278108, 552268, 1098148, 2189908, 4379816, 8776356, 17596496, 35263836, 70598516, 141197032, 282208592, 563931612, 1127077552, 2253369432, 4506738864, 9015534644
Offset: 0

Views

Author

Paul Curtz, Dec 07 2009

Keywords

Comments

The recurrence shows that the sequence and its successive differences are identical to their fifth differences (see A135356).

Programs

  • Mathematica
    LinearRecurrence[{5,-10,10,-5,2},{1,6,16,36,76},40] (* Harvey P. Dale, Dec 09 2013 *)

Formula

a(n+1)-2*a(n) = 4*A105371(n-1) = 4*A138110(4,n).
a(n) = 5*a(n-1)-10*a(n-2)+10*a(n-3)-5*a(n-4)+2*a(n-5).
G.f.: (1+x-4*x^2+6*x^3+x^4)/((1-2*x)*(x^4-2*x^3+4*x^2-3*x+1)).

Extensions

Edited and extended by R. J. Mathar, Dec 15 2009, Mar 02 2010
Showing 1-2 of 2 results.