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 1-3 of 3 results.

A291000 p-INVERT of (1,1,1,1,1,...), where p(S) = 1 - S - S^2 - S^3.

Original entry on oeis.org

1, 3, 9, 26, 74, 210, 596, 1692, 4804, 13640, 38728, 109960, 312208, 886448, 2516880, 7146144, 20289952, 57608992, 163568448, 464417728, 1318615104, 3743926400, 10630080640, 30181847168, 85694918912, 243312448256, 690833811712, 1961475291648, 5569190816256
Offset: 0

Views

Author

Clark Kimberling, Aug 22 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).
In the following guide to p-INVERT sequences using s = (1,1,1,1,1,...) = A000012, in some cases t(1,1,1,1,1,...) is a shifted version of the cited sequence:
p(S) t(1,1,1,1,1,...)
1 - S A000079
1 - S^2 A000079
1 - S^3 A024495
1 - S^4 A000749
1 - S^5 A139761
1 - S^6 A290993
1 - S^7 A290994
1 - S^8 A290995
1 - S - S^2 A001906
1 - S - S^3 A116703
1 - S - S^4 A290996
1 - S^3 - S^6 A290997
1 - S^2 - S^3 A095263
1 - S^3 - S^4 A290998
1 - 2 S^2 A052542
1 - 3 S^2 A002605
1 - 4 S^2 A015518
1 - 5 S^2 A163305
1 - 6 S^2 A290999
1 - 7 S^2 A291008
1 - 8 S^2 A291001
(1 - S)^2 A045623
(1 - S)^3 A058396
(1 - S)^4 A062109
(1 - S)^5 A169792
(1 - S)^6 A169793
(1 - S^2)^2 A024007
1 - 2 S - 2 S^2 A052530
1 - 3 S - 2 S^2 A060801
(1 - S)(1 - 2 S) A053581
(1 - 2 S)(1 - 3 S) A291002
(1 - S)(1 - 2 S)(1 - 3 S)(1 - 4 S) A291003
(1 - 2 S)^2 A120926
(1 - 3 S)^2 A291004
1 + S - S^2 A000045 (Fibonacci numbers starting with -1)
1 - S - S^2 - S^3 A291000
1 - S - S^2 - S^3 - S^4 A291006
1 - S - S^2 - S^3 - S^4 - S^5 A291007
1 - S^2 - S^4 A290990
(1 - S)(1 - 3 S) A291009
(1 - S)(1 - 2 S)(1 - 3 S) A291010
(1 - S)^2 (1 - 2 S) A291011
(1 - S^2)(1 - 2 S) A291012
(1 - S^2)^3 A291013
(1 - S^3)^2 A291014
1 - S - S^2 + S^3 A045891
1 - 2 S - S^2 + S^3 A291015
1 - 3 S + S^2 A136775
1 - 4 S + S^2 A291016
1 - 5 S + S^2 A291017
1 - 6 S + S^2 A291018
1 - S - S^2 - S^3 + S^4 A291019
1 - S - S^2 - S^3 - S^4 + S^5 A291020
1 - S - S^2 - S^3 + S^4 + S^5 A291021
1 - S - 2 S^2 + 2 S^3 A175658
1 - 3 S^2 + 2 S^3 A291023
(1 - 2 S^2)^2 A291024
(1 - S^3)^3 A291143
(1 - S - S^2)^2 A209917

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x); p = 1 - s - s^2 - s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A000012 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291000 *)

Formula

G.f.: (-1 + x - x^2)/(-1 + 4 x - 4 x^2 + 2 x^3).
a(n) = 4*a(n-1) - 4*a(n-2) + 2*a(n-3) for n >= 4.

A258837 a(n) = 1 - n^2.

Original entry on oeis.org

1, 0, -3, -8, -15, -24, -35, -48, -63, -80, -99, -120, -143, -168, -195, -224, -255, -288, -323, -360, -399, -440, -483, -528, -575, -624, -675, -728, -783, -840, -899, -960, -1023, -1088, -1155, -1224, -1295, -1368, -1443, -1520, -1599, -1680, -1763, -1848
Offset: 0

Views

Author

Vincenzo Librandi, Jun 12 2015

Keywords

Crossrefs

Sequences of the type 1-n^k: A024000 (k=1), this sequence (k=2), A024001 (k=3), A024002 (k=4), A024003 (k=5), A024004 (k=6), A024005 (k=7), A024006 (k=8), A024007 (k=9), A024008 (k=10), A024009 (k=11), A024010 (k=12).

Programs

  • Magma
    [1-n^2: n in [0..50]];
    
  • Magma
    I:=[1,0,-3]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+Self(n-3): n in [1..50]];
    
  • Mathematica
    Table[1 - n^2, {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {1, 0, -3}, 50]
  • PARI
    my(x='x+O('x^50)); Vec((1-3*x)/(1-x)^3) \\ G. C. Greubel, May 11 2017

Formula

G.f.: (1-3*x)/(1-x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
a(n) = -A067998(n+1). - Joerg Arndt, Jun 13 2015
a(n) = (-1)^n*A131386(n+1). - Bruno Berselli, Jun 15 2015
E.g.f.: (1 - x - x^2)*exp(x). - G. C. Greubel, May 11 2017
Sum_{n>=2} 1/a(n) = -3/4. - Amiram Eldar, Feb 17 2023

A258810 a(n) = n^9 - 1.

Original entry on oeis.org

0, 511, 19682, 262143, 1953124, 10077695, 40353606, 134217727, 387420488, 999999999, 2357947690, 5159780351, 10604499372, 20661046783, 38443359374, 68719476735, 118587876496, 198359290367, 322687697778, 511999999999, 794280046580, 1207269217791, 1801152661462
Offset: 1

Views

Author

Vincenzo Librandi, Jun 11 2015

Keywords

Crossrefs

Cf. A024007, similar sequences listed in A258807.

Programs

  • Magma
    [n^9-1: n in [1..40]];
    
  • Magma
    I:=[0,511,19682, 262143,1953124,10077695,40353606,134217727,387420488, 999999999]; [n le 10 select I[n] else 10*Self(n-1)-45*Self(n-2)+120*Self(n-3)-210*Self(n-4)+252*Self(n-5)-210*Self(n-6)+120*Self(n-7)-45*Self(n-8)+10*Self(n-9)-Self(n-10): n in [1..40]];
  • Mathematica
    Table[n^9 - 1, {n, 33}] (* or *) LinearRecurrence[{10, -45, 120, -210, 252, -210, 120, -45, 10, -1}, {0, 511, 19682, 262143, 1953124, 10077695, 40353606, 134217727, 387420488, 999999999}, 40]

Formula

G.f.: x^2*(511 + 14572*x + 88318*x^2 + 156064*x^3 + 88360*x^4 + 14524*x^5 + 538*x^6 - 8*x^7 + x^8)/(1-x)^10.
a(n) = 10*a(n-1)-45*a(n-2)+120*a(n-3)-210*a(n-4)+252*a(n-5)-210*a(n-6)+120*a(n-7)-45*a(n-8)+10*a(n-9)-a(n-10).
Showing 1-3 of 3 results.