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.

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A016218 Expansion of 1/((1-x)*(1-4*x)*(1-5*x)).

Original entry on oeis.org

1, 10, 71, 440, 2541, 14070, 75811, 400900, 2091881, 10808930, 55442751, 282806160, 1436400421, 7271480590, 36715316891, 185008240220, 930767824161, 4676745613050, 23475354034231, 117743274047080, 590182385739101, 2956775990710310, 14807336201610771
Offset: 0

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Author

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Crossrefs

Programs

Formula

From Vincenzo Librandi, Feb 10 2011: (Start)
a(n) = a(n-1) + 5^(n+1) - 4^(n+1), n >= 1.
a(n) = 9*a(n-1) - 20*a(n-2) + 1, n >= 2. (End)
a(n) = 1/12 - 4^(n+2)/3 + 5^(n+2)/4. - R. J. Mathar, Mar 15 2011

A016256 Expansion of 1/((1-x)*(1-8*x)*(1-9*x)).

Original entry on oeis.org

1, 18, 235, 2700, 28981, 298278, 2984095, 29253600, 282456361, 2695498938, 25486623955, 239196683700, 2231306698141, 20710052641998, 191416812647815, 1762962024789000, 16188343910770321, 148268580698287458, 1355005110295423675, 12359749064745505500
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Maple
    a:=n->sum(9^(n-j)-8^(n-j),j=0..n): seq(a(n), n=1..19); # Zerinvary Lajos, Jan 04 2007
  • Mathematica
    Table[(-8^(n + 2) + 7*9^(n + 1) + 1)/56, {n, 40}] (* and *) CoefficientList[Series[1/((1 - z) (1 - 8*z) (1 - 9*z)), {z, 0, 40}], z] (* Vladimir Joseph Stephan Orlovsky, Jul 21 2011 *)
  • PARI
    Vec(1/((1-x)*(1-8*x)*(1-9*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 23 2012

Formula

G.f.: 1/((1-x)*(1-8*x)*(1-9*x)).
a(n) = 17*a(n-1) - 72*a(n-2) + 1. - Vincenzo Librandi, Feb 10 2011
a(n) = 9^(n+2)/8 - 8^(n+2)/7 + 1/56. - R. J. Mathar, Mar 14 2011
a(n) = 18*a(n-1) - 89*a(n-2) + 72*a(n-3). - Wesley Ivan Hurt, Apr 20 2023

A083713 a(n) = (8^n - 1)*3/7.

Original entry on oeis.org

0, 3, 27, 219, 1755, 14043, 112347, 898779, 7190235, 57521883, 460175067, 3681400539, 29451204315, 235609634523, 1884877076187, 15079016609499, 120632132875995, 965057063007963, 7720456504063707, 61763652032509659
Offset: 0

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Author

Klaus Brockhaus, Jun 14 2003

Keywords

Comments

Fixed points of the mapping defined by A067585. In binary these numbers show a regular pattern: 0, 11, 11011, 11011011, 11011011011, etc.
From Reinhard Zumkeller, Feb 22 2010: (Start)
a(n) = A173593(6*n-5) for n > 0:
terms of A173593 beginning and ending with digits '11' in binary representation;
for n > 0: a(n) = A033129(3*n-1); a(n) - a(n-1) = A103333(n). (End)

Examples

			From _Zerinvary Lajos_, Jan 14 2007: (Start)
Octal..........decimal:
0....................0
3....................3
33..................27
333................219
3333..............1755
33333............14043
333333..........112347
3333333.........898779
33333333.......7190235
333333333.....57521883
3333333333...460175067
etc. (End)
		

Crossrefs

Programs

  • Mathematica
    (3/7)(8^Range[0,20]-1) (* or *) LinearRecurrence[{9,-8},{0,3},30] (* or *) NestList[8#+3&,0,30] (* Harvey P. Dale, Jun 06 2013 *)
  • PARI
    a(n)=(8^n-1)*3/7 \\ Charles R Greathouse IV, Oct 07 2015

Formula

a(n) = 3*A023001(n).
Recursion: a(0) = 0, a(n+1) = (((a(n)*2)*2+1)*2+1).
a(n) = 8*a(n-1) + 3 (with a(0)=0). - Vincenzo Librandi, Aug 08 2010
a(0)=0, a(1)=3, a(n) = 9*a(n-1) - 8*a(n-2). - Harvey P. Dale, Jun 06 2013
From Stefano Spezia, Feb 23 2025: (Start)
G.f.: 3*x/((1 - x)*(1 - 8*x)).
E.g.f.: 3*exp(x)*(exp(7*x) - 1)/7. (End)

A218750 a(n) = (47^n - 1)/46.

Original entry on oeis.org

0, 1, 48, 2257, 106080, 4985761, 234330768, 11013546097, 517636666560, 24328923328321, 1143459396431088, 53742591632261137, 2525901806716273440, 118717384915664851681, 5579717091036248029008, 262246703278703657363377, 12325595054099071896078720
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 47 (A009991).

Crossrefs

Programs

Formula

a(n) = floor(47^n/46).
G.f.: x/(47*x^2-48*x+1) = x/((1-x)*(1-47*x)). [Colin Barker, Nov 06 2012]
a(0)=0, a(n) = 47*a(n-1) + 1. - Vincenzo Librandi, Nov 08 2012
a(n) = 48*a(n-1) - 47*a(n-2). - Wesley Ivan Hurt, Jan 25 2022
E.g.f.: exp(24*x)*sinh(23*x)/23. - Elmo R. Oliveira, Aug 27 2024

A033118 Base 8 digits are, in order, the first n terms of the periodic sequence with initial period 1,0.

Original entry on oeis.org

1, 8, 65, 520, 4161, 33288, 266305, 2130440, 17043521, 136348168, 1090785345, 8726282760, 69810262081, 558482096648, 4467856773185, 35742854185480, 285942833483841, 2287542667870728, 18300341342965825, 146402730743726600
Offset: 1

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Author

Keywords

Comments

Partial sums of A015565. - Mircea Merca, Dec 28 2010

Crossrefs

Pairwise sums are (8^n - 1)/7 (A023001).

Programs

  • Magma
    [Round((8*8^n-8)/63): n in [1..30]]; // Vincenzo Librandi, Jun 25 2011
  • Maple
    seq(1/7*floor(8^(n+1)/9),n=1..22); # Mircea Merca, Dec 27 2010
  • Mathematica
    Table[FromDigits[PadRight[{},n,{1,0}],8],{n,20}] (* or *) LinearRecurrence[ {8,1,-8},{1,8,65},20] (* Harvey P. Dale, Jan 20 2021 *)

Formula

a(n) = 8*a(n-1) + a(n-2) - 8*a(n-3).
a(n) = 2^(3*n+3)/63 - 1/14 - (-1)^n/18. - R. J. Mathar, Jan 08 2011
From Paul Barry, Apr 04 2008: (Start)
G.f. x/((1-x^2)*(1-8*x));
a(n) = (1/3)*Sum_{k=0..n} A001045(3k). (End)
a(n) = floor(8^(n+1)/9)/7 = floor((8*8^n-1)/63) = round((8*8^n-8)/63) = round((16*8^n-9)/63) = ceiling((8*8^n-8)/63). a(n) = a(n-2) + 8^(n-1), n > 2. - Mircea Merca, Dec 28 2010

A218726 a(n) = (23^n - 1)/22.

Original entry on oeis.org

0, 1, 24, 553, 12720, 292561, 6728904, 154764793, 3559590240, 81870575521, 1883023236984, 43309534450633, 996119292364560, 22910743724384881, 526947105660852264, 12119783430199602073, 278755018894590847680, 6411365434575589496641, 147461404995238558422744
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 23, q-integers for q=23: diagonal k=1 in triangle A022187.
Partial sums are in A014909. Also, the sequence is related to A014941 by A014941(n) = n*a(n) - Sum{a(i), i=0..n-1} for n > 0. - Bruno Berselli, Nov 07 2012

Crossrefs

Programs

Formula

From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1-x)*(1-23*x)).
a(n) = floor(23^n/22).
a(n) = 24*a(n-1) - 23*a(n-2). (End)
E.g.f.: exp(12*x)*sinh(11*x)/11. - Elmo R. Oliveira, Aug 27 2024

A218732 a(n) = (29^n - 1)/28.

Original entry on oeis.org

0, 1, 30, 871, 25260, 732541, 21243690, 616067011, 17865943320, 518112356281, 15025258332150, 435732491632351, 12636242257338180, 366451025462807221, 10627079738421409410, 308185312414220872891, 8937374060012405313840, 259183847740359754101361
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 29 (A009973).

Crossrefs

Programs

  • Magma
    [n le 2 select n-1 else 30*Self(n-1)-29*Self(n-2): n in [1..20]]; // Vincenzo Librandi, Nov 07 2012
    
  • Mathematica
    LinearRecurrence[{30, -29}, {0, 1}, 30] (* Vincenzo Librandi, Nov 07 2012 *)
  • Maxima
    A218732(n):=(29^n-1)/28$
    makelist(A218732(n),n,0,30); /* Martin Ettl, Nov 07 2012 */
  • PARI
    a(n)=29^n\28
    

Formula

a(n) = floor(29^n/28).
G.f.: x/((1-x)*(1-29*x)). - Vincenzo Librandi, Nov 07 2012
a(n) = 30*a(n-1) - 29*a(n-2). - Vincenzo Librandi, Nov 07 2012
E.g.f.: exp(15*x)*sinh(14*x)/14. - Elmo R. Oliveira, Aug 27 2024

A218733 a(n) = (30^n - 1)/29.

Original entry on oeis.org

0, 1, 31, 931, 27931, 837931, 25137931, 754137931, 22624137931, 678724137931, 20361724137931, 610851724137931, 18325551724137931, 549766551724137931, 16492996551724137931, 494789896551724137931, 14843696896551724137931, 445310906896551724137931, 13359327206896551724137931
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 30 (A009974).

Crossrefs

Programs

Formula

a(n) = floor(30^n/29).
From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1-x)*(1-30*x)).
a(n) = 31*a(n-1) - 30*a(n-2). (End)
E.g.f.: exp(x)*(exp(29*x) - 1)/29. - Elmo R. Oliveira, Aug 29 2024

A218740 a(n) = (37^n - 1)/36.

Original entry on oeis.org

0, 1, 38, 1407, 52060, 1926221, 71270178, 2636996587, 97568873720, 3610048327641, 133571788122718, 4942156160540567, 182859777940000980, 6765811783780036261, 250335035999861341658, 9262396331994869641347, 342708664283810176729840, 12680220578500976539004081
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 37 (A009981).

Crossrefs

Programs

Formula

From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1 - x)*(1 - 37*x)).
a(n) = 38*a(n-1) - 37*a(n-2).
a(n) = floor(37^n/36). (End)
E.g.f.: exp(x)*(exp(36*x) - 1)/36. - Stefano Spezia, Mar 28 2023

A218744 a(n) = (41^n - 1)/40.

Original entry on oeis.org

0, 1, 42, 1723, 70644, 2896405, 118752606, 4868856847, 199623130728, 8184548359849, 335566482753810, 13758225792906211, 564087257509154652, 23127577557875340733, 948230679872888970054, 38877457874788447772215, 1593975772866326358660816, 65353006687519380705093457
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 41 (A009985).

Crossrefs

Programs

Formula

a(n) = floor(41^n/40).
G.f.: x/((1-x)*(1-41*x)). - Vincenzo Librandi, Nov 07 2012
a(n) = 42*a(n-1) - 41*a(n-2). - Vincenzo Librandi, Nov 07 2012
E.g.f.: exp(21*x)*sinh(20*x)/20. - Elmo R. Oliveira, Aug 27 2024
Previous Showing 31-40 of 83 results. Next