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.

A292327 p-INVERT of the Fibonacci sequence (A000045), where p(S) = (1 - S)^2.

Original entry on oeis.org

2, 5, 14, 38, 102, 271, 714, 1868, 4858, 12569, 32374, 83058, 212350, 541219, 1375570, 3487384, 8821170, 22266413, 56098206, 141087934, 354268502, 888238903, 2223968666, 5561234916, 13889778218, 34652529473, 86361653126, 215021205770, 534861620718
Offset: 0

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Author

Clark Kimberling, Sep 15 2017

Keywords

Comments

Suppose s = (c(0), c(1), c(2), ...) is a sequence and p(S) is a polynomial. Let S(x) = c(0)*x + c(1)*x^2 + c(2)*x^3 + ... and T(x) = (-p(0) + 1/p(S(x)))/x. The p-INVERT of s is the sequence t(s) of coefficients in the Maclaurin series for T(x). Taking p(S) = 1 - S gives the "INVERT" transform of s, so that p-INVERT is a generalization of the "INVERT" transform (e.g., A033453).

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x - x^2); p = (1 - s)^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A000045 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A292327 *)

Formula

G.f.: -(2 + x)*(-1 + 2*x)/(-1 + 2*x + x^2)^2.
a(n) = 4*a(n-1) - 2*a(n-2) - 4*a(n-3) - a(n-4) for n >= 5.
a(n) = A006645(n+1) +2*A000129(n+1). - R. J. Mathar, Jul 08 2022

A292329 p-INVERT of the Fibonacci sequence (A000045), where p(S) = 1 - S^3.

Original entry on oeis.org

0, 0, 1, 3, 9, 23, 57, 138, 332, 798, 1920, 4626, 11157, 26925, 64997, 156921, 378861, 914692, 2208324, 5331444, 12871324, 31074180, 75019701, 181113471, 437246349, 1055605659, 2548456957, 6152518758, 14853493752, 35859505946, 86572506132, 209004519918
Offset: 0

Views

Author

Clark Kimberling, Sep 15 2017

Keywords

Comments

Suppose s = (c(0), c(1), c(2), ...) is a sequence and p(S) is a polynomial. Let S(x) = c(0)*x + c(1)*x^2 + c(2)*x^3 + ... and T(x) = (-p(0) + 1/p(S(x)))/x. The p-INVERT of s is the sequence t(s) of coefficients in the Maclaurin series for T(x). Taking p(S) = 1 - S gives the "INVERT" transform of s, so that p-INVERT is a generalization of the "INVERT" transform (e.g., A033453).

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x - x^2); p = 1 - s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A000045 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A292329 *)

Formula

G.f.: -(x^2/((-1 + 2 x + x^2) (1 - x - x^2 + x^3 + x^4))).
a(n) = 3*a(n-1) - 4*a(n-3) + 3*a(n-5) + a(n-6) for n >= 7.
Showing 1-2 of 2 results.