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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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

A218746 a(n) = (43^n - 1)/42.

Original entry on oeis.org

0, 1, 44, 1893, 81400, 3500201, 150508644, 6471871693, 278290482800, 11966490760401, 514559102697244, 22126041415981493, 951419780887204200, 40911050578149780601, 1759175174860440565844, 75644532518998944331293, 3252714898316954606245600, 139866740627629048068560801
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 43 (A009987).
0 followed by the binomial transform of A170762. - R. J. Mathar, Jul 18 2015

Crossrefs

Programs

Formula

G.f.: x/((1-x)*(1-43*x)). - Vincenzo Librandi, Nov 07 2012
a(n) = 44*a(n-1) - 43*a(n-2). - Vincenzo Librandi, Nov 07 2012
a(n) = floor(43^n/42). - Vincenzo Librandi, Nov 07 2012
E.g.f.: exp(22*x)*sinh(21*x)/21. - Elmo R. Oliveira, Aug 27 2024

A353144 Decimal repunits written in base 5.

Original entry on oeis.org

0, 1, 21, 421, 13421, 323421, 12023421, 241023421, 10321023421, 211421023421, 4233421023421, 140223421023421, 3310023421023421, 121201023421023421, 2424021023421023421, 104030421023421023421, 2131113421023421023421, 43122323421023421023421, 1413002023421023421023421
Offset: 0

Views

Author

Seiichi Manyama, Apr 26 2022

Keywords

Crossrefs

Programs

  • PARI
    a(n) = fromdigits(digits((10^n-1)/9, 5));

Formula

a(n) = A007091(A002275(n)).

A016234 Expansion of 1/((1-x) * (1-5*x) * (1-9*x)).

Original entry on oeis.org

1, 15, 166, 1650, 15631, 144585, 1320796, 11984820, 108351661, 977606355, 8810664226, 79357013190, 714518294491, 6432190529325, 57897344158456, 521114244398760, 4690218934452121, 42212924084385495, 379921085131051486, 3419313608037373530, 30773941681625912551
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[1/((1-x)(1-5x)(1-9x)),{x,0,30}],x] (* or *) LinearRecurrence[{15,-59,45},{1,15,166},30] (* Harvey P. Dale, Oct 16 2014 *)
  • PARI
    Vec(1/((1-x)*(1-5*x)*(1-9*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012
    
  • PARI
    a(n) = (9^(n+2) - 2*5^(n+2) + 1)/32; \\ Joerg Arndt, Aug 13 2013

Formula

a(0)=1, a(1)=15, a(n) = 14*a(n-1) - 45*a(n-2) + 1. - Vincenzo Librandi, Feb 10 2011
a(n) = (9^(n+2) - 2*5^(n+2) + 1)/32. - Yahia Kahloune, Aug 13 2013
a(0)=1, a(1)=15, a(2)=166, a(n) = 15*a(n-1) - 59*a(n-2) + 45*a(n-3). - Harvey P. Dale, Oct 16 2014
O.g.f.: see the name.
E.g.f.: (d^2/dx^2) (exp(x)*((exp(4*x) - 1)^2)/(4^2*2!)) = exp(x)*(1 - 50*exp(4*x) + 81*exp(8*x))/32.
From Seiichi Manyama, May 05 2025: (Start)
a(n) = Sum_{k=0..n} 4^k * binomial(n+2,k+2) * Stirling2(k+2,2).
a(n) = Sum_{k=0..n} (-4)^k * 9^(n-k) * binomial(n+2,k+2) * Stirling2(k+2,2). (End)

A125833 Numbers whose base-5 representation is 333333.......3.

Original entry on oeis.org

0, 3, 18, 93, 468, 2343, 11718, 58593, 292968, 1464843, 7324218, 36621093, 183105468, 915527343, 4577636718, 22888183593, 114440917968, 572204589843, 2861022949218, 14305114746093, 71525573730468, 357627868652343
Offset: 0

Views

Author

Zerinvary Lajos, Feb 03 2007

Keywords

Examples

			Base 5.................decimal
0.........................0
3.........................3
33.......................18
333......................93
3333....................468
33333..................2343
333333................11718
3333333...............58593
33333333.............292968, etc.
		

Crossrefs

Cf. A003463.

Programs

  • GAP
    List([0..30], n-> 3*(5^n -1)/4); G. C. Greubel, Aug 03 2019
  • Magma
    [3*(5^n -1)/4: n in [0..30]]; // G. C. Greubel, Aug 03 2019
    
  • Maple
    seq(3*(5^n-1)/4, n=0..30);
  • Mathematica
    Table[FromDigits[PadRight[{},n,3],5],{n,0,30}] (* or *) LinearRecurrence[ {6,-5},{0,3},30] (* Harvey P. Dale, Sep 23 2016 *)
    3*(5^Range[0,30] -1)/4 (* G. C. Greubel, Aug 03 2019 *)
  • PARI
    vector(30, n, n--; 3*(5^n -1)/4) \\ G. C. Greubel, Aug 03 2019
    
  • Sage
    [3*(5^n -1)/4 for n in (0..30)] # G. C. Greubel, Aug 03 2019
    

Formula

a(n) = 3*(5^n - 1)/4.
a(n) = 5*a(n-1) + 3 for n > 0, a(0)=0. - Vincenzo Librandi, Sep 30 2010
From G. C. Greubel, Aug 03 2019: (Start)
a(n) = 3*A003463(n).
G.f.: 3*x/((1-x)*(1-5*x)).
E.g.f.: 3*(exp(5*x) - exp(x))/4. (End)

A157832 Triangle read by rows: the coefficient [x^k] of the polynomial Product_{i=1..n} (5^(i-1)-x) in row n, column k, 0 <= k <= n.

Original entry on oeis.org

1, 1, -1, 5, -6, 1, 125, -155, 31, -1, 15625, -19500, 4030, -156, 1, 9765625, -12203125, 2538250, -101530, 781, -1, 30517578125, -38144531250, 7944234375, -319819500, 2542155, -3906, 1, 476837158203125, -596038818359375
Offset: 0

Views

Author

Roger L. Bagula, Mar 07 2009

Keywords

Comments

Except for n=0, the row sums are zero.
Triangle T(n,k), 0 <= k <= n, read by rows given by [1,q-1,q^2,q^3-q,q^4,q^5-q^2,q^6,q^7-q^3,q^8,...] DELTA [ -1,0,-q,0,-q^2,0,-q^3,0,-q^4,0,...] (for q=5)= [1,4,25,120,625,3100,15625,...] DELTA [ -1,0,-5,0,-25,0,-125,0,-625,0,...] where DELTA is the operator defined in A084938. - Philippe Deléham, Mar 10 2009

Examples

			Triangle begins
  1;
  1, -1;
  5, -6, 1;
  125, -155, 31, -1;
  15625, -19500, 4030, -156, 1;
  9765625, -12203125, 2538250, -101530, 781, -1;
  30517578125, -38144531250, 7944234375, -319819500, 2542155, -3906, 1;
  476837158203125, -596038818359375, 124166806640625, -5005123921875, 40040991375, -63573405, 19531, -1;
		

Crossrefs

Cf. A135950, A157783, A109345 (first column), A003463 (first subdiagonal).

Programs

  • Maple
    A157832 := proc(n,k)
            product( 5^(i-1)-x,i=1..n) ;
            coeftayl(%,x=0,k) ;
    end proc: # R. J. Mathar, Oct 15 2013
  • Mathematica
    p[x_, n_] = If[n == 0, 1, Product[q^(i - 1) - x, {i, 1, n}]];
    q = 5;
    Table[CoefficientList[p[x, n], x], {n, 0, 10}];
    Flatten[%]

A218728 a(n) = (25^n - 1)/24.

Original entry on oeis.org

0, 1, 26, 651, 16276, 406901, 10172526, 254313151, 6357828776, 158945719401, 3973642985026, 99341074625651, 2483526865641276, 62088171641031901, 1552204291025797526, 38805107275644938151, 970127681891123453776, 24253192047278086344401, 606329801181952158610026
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 25 (A009969); q-integers for q=25.
Partial sums are in A014914. Also, the sequence is related to A014943 by A014943(n) = n*a(n) - Sum_{i=0..n-1} a(i) for n > 0. - Bruno Berselli, Nov 07 2012

Crossrefs

Programs

Formula

a(n) = floor(25^n/24).
From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1-x)*(1-25*x)).
a(n) = 26*a(n-1) - 25*a(n-2). (End)
E.g.f.: exp(13*x)*sinh(12*x)/12. - Elmo R. Oliveira, Aug 27 2024
a(n) = 25*a(n-1) + 1. - Jerzy R Borysowicz, Sep 05 2025

A218743 a(n) = (40^n - 1)/39.

Original entry on oeis.org

0, 1, 41, 1641, 65641, 2625641, 105025641, 4201025641, 168041025641, 6721641025641, 268865641025641, 10754625641025641, 430185025641025641, 17207401025641025641, 688296041025641025641, 27531841641025641025641, 1101273665641025641025641, 44050946625641025641025641
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 40 (A009983).

Crossrefs

Programs

  • Magma
    [n le 2 select n-1 else 41*Self(n-1) - 40*Self(n-2): n in [1..20]]; // Vincenzo Librandi, Nov 07 2012
  • Mathematica
    LinearRecurrence[{41, -40}, {0, 1}, 30] (* Vincenzo Librandi, Nov 07 2012 *)
  • Maxima
    A218743(n):=floor(40^n/39)$ makelist(A218743(n),n,0,30); /* Martin Ettl, Nov 05 2012 */
    
  • PARI
    a(n)=40^n\39
    

Formula

a(n) = floor(40^n/39).
From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1-x)*(1-40*x)).
a(n) = 41*a(n-1) - 40*a(n-2). (End)
E.g.f.: exp(x)*(exp(39*x) - 1)/39. - Elmo R. Oliveira, Aug 29 2024
Previous Showing 51-60 of 103 results. Next