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.

A138232 First differences of A138231.

Original entry on oeis.org

1, 0, 0, 1, -2, 2, -4, 2, -4, 0, 0, -4, 8, -8, 16, -8, 16, 0, 0, 16, -32, 32, -64, 32, -64, 0, 0, -64, 128, -128, 256, -128, 256, 0, 0, 256, -512, 512, -1024, 512, -1024, 0, 0, -1024, 2048, -2048, 4096, -2048, 4096, 0, 0, 4096, -8192, 8192, -16384, 8192, -16384, 0, 0, -16384, 32768
Offset: 0

Views

Author

Paul Curtz, May 05 2008

Keywords

Comments

The sequence contains 2 copies of 1 and 3 copies of the higher powers 2^j (up to sign).

Links

Crossrefs

Cf. A000079, A131577.

Programs

  • Mathematica
    LinearRecurrence[{0,2,0,-2},{1,0,0,1},70] (* Harvey P. Dale, Apr 23 2022 *)

Formula

a(n) = 2a(n-2)-2a(n-4). a(n) = -4a(n-8).
a(2n) = (-1)^(n+1)*A090132(n). a(2n+1) = A009545(n).
O.g.f.: (x-1)(x^2-x-1)/(1-2x^2+2x^4). - R. J. Mathar, Jul 08 2008

Extensions

Edited by R. J. Mathar, Jul 08 2008

A138614 Expansion of (2*x-1)*(x^2-x-1) / ( 1-2*x^2+2*x^4 ).

Original entry on oeis.org

1, -1, -1, 0, -4, 2, -6, 4, -4, 4, 4, 0, 16, -8, 24, -16, 16, -16, -16, 0, -64, 32, -96, 64, -64, 64, 64, 0, 256, -128, 384, -256, 256, -256, -256, 0, -1024, 512, -1536, 1024, -1024, 1024, 1024, 0, 4096, -2048, 6144, -4096, 4096, -4096, -4096
Offset: 0

Views

Author

Paul Curtz, May 14 2008

Keywords

Links

Programs

  • Mathematica
    LinearRecurrence[{0,2,0,-2},{1,-1,-1,0},60] (* Harvey P. Dale, Jul 31 2023 *)

Formula

a(n)= -4a(n-8).
a(n) = A138231(n+1)-2*A138231(n).
a(n) = A138232(n)- A138231(n).
Showing 1-2 of 2 results.

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