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 1-10 of 64 results. Next

A291219 p-INVERT of (0,1,0,1,0,1,...), where p(S) = 1 - S - S^3.

Original entry on oeis.org

1, 1, 3, 5, 11, 21, 42, 83, 163, 323, 635, 1255, 2473, 4880, 9625, 18985, 37451, 73869, 145715, 287421, 566954, 1118331, 2205947, 4351307, 8583091, 16930447, 33395857, 65874464, 129939569, 256310161, 505580371, 997274197, 1967156763, 3880282533, 7653987242
Offset: 0

Views

Author

Clark Kimberling, Aug 24 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 = (1,0,1,0,1,...) = A000035, in some cases t(1,0,1,0,1,...) is a shifted version of the indicated sequence.
p(S) t(1,0,1,0,1,...)
1 - S A000045 (Fibonacci numbers)
1 - S^2 A147600
1 - S^3 A291217
1 - S^5 A291218
1 - S - S^2 A289846
1 - S - S^3 A291219
1 - S - S^4 A291220
1 - S^3- S^6 A291221
1 - S^2- S^3 A291222
1 - S^3- S^4 A291223
1 - 2S A052542
1 - 3S A006190
(1 - S)^2 A239342
(1 - S)^3 A276129
(1 - S)^4 A291224
(1 - S)^5 A291225
(1 - S)^6 A291226
1 - S - 2 S^2 A291227
1 - 2 S - 2 S^2 A291228
1 - 3 S - 2 S^2 A060801
(1 - S)(1 - 2 S) A291229
(1 - S)(1 - 2 S)(1 - 3 S) A291230
(1 - S)(1 - 2 S)(1 - 3 S)( 1 - 4 S) A291231
(1 - 2 S)^2 A291264
(1 - 3 S)^2 A291232
1 - S - S^2 - S^3 A291233
1 - S - S^2 - S^3 - S^4 A291234
1 - S - S^2 - S^3 - S^4 - S^5 A291235
(1 - S)(1 - 3 S) A291236
(1 - S)(1 - 2S)( 1 - 4S) A291237
(1 - S)^2 (1 - 2S) A291238
(1 - S^2) (1 - 2S) A291239
(1 - S^3)^2 A291240
1 - S - S^2 + S^3 A291241
1 - 2 S - S^2 + S^3 A291242
1 - 3 S + S^2 A291243
1 - 4 S + S^2 A291244
1 - 5 S + S^2 A291245
1 - 6 S + S^2 A291246
1 - S - S^2 - S^3 + S^4 A291247
1 - S - S^2 - S^3 - S^4 + S^5 A291248
1 - S - S^2 - S^3 + S^4 + S^5 A291249
1 - S - 2 S^2 + 2 S^3 A291250
1 - 3 S^2 + 2 S^3 A291251 (includes negative terms)
(1 - S^3)^3 A291252
(1 - S - S^2)^2 A291253
(1 - 2 S - S^2)^2 A291254
(1 - S - 2 S^2)^2 A291255

Crossrefs

Programs

  • Magma
    I:=[1,1,3,5,11,21]; [n le 6 select I[n] else Self(n-1)+3*Self(n-2)-Self(n-3)-3*Self(n-4)+Self(n-5)+Self(n-6): n in [1..45]]; // Vincenzo Librandi, Aug 25 2017
  • Mathematica
    z = 60; s = x/(1 - x^2); p = 1 - s - s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A000035 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291219 *)
    LinearRecurrence[{1, 3, -1, -3, 1, 1}, {1, 1, 3, 5, 11, 21}, 50] (* Vincenzo Librandi, Aug 25 2017 *)

Formula

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

A291382 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 2 S - S^2.

Original entry on oeis.org

2, 7, 22, 70, 222, 705, 2238, 7105, 22556, 71608, 227332, 721705, 2291178, 7273743, 23091762, 73308814, 232731578, 738846865, 2345597854, 7446508273, 23640235416, 75050038224, 238259397096, 756395887969, 2401310279090, 7623377054503, 24201736119310
Offset: 0

Views

Author

Clark Kimberling, Sep 04 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 = (1,1,0,0,0,...) = A019590, in some cases t(1,1,0,0,0,...) is a shifted version of the cited sequence:
p(S) t(1,1,0,0,0,...)
1 - S A000045 (Fibonacci numbers)
1 - S^2 A094686
1 - S^3 A115055
1 - S^4 A291379
1 - S^5 A281380
1 - S^6 A281381
1 - 2 S A002605
1 - 3 S A125145
(1 - S)^2 A001629
(1 - S)^3 A001628
(1 - S)^4 A001629
(1 - S)^5 A001873
(1 - S)^6 A001874
1 - S - S^2 A123392
1 - 2 S - S^2 A291382
1 - S - 2 S^2 A124861
1 - 2 S - S^2 A291383
(1 - 2 S)^2 A073388
(1 - 3 S)^2 A291387
(1 - 5 S)^2 A291389
(1 - 6 S)^2 A291391
(1 - S)(1 - 2 S) A291393
(1 - S)(1 - 3 S) A291394
(1 - 2 S)(1 - 3 S) A291395
(1 - S)(1 - 2 S) A291393
(1 - S)(1 - 2 S)(1 - 3 S) A291396
1 - S - S^3 A291397
1 - S^2 - S^3 A291398
1 - S - S^2 - S^3 A186812
1 - S - S^2 - S^3 - S^4 A291399
1 - S^2 - S^4 A291400
1 - S - S^4 A291401
1 - S^3 - S^4 A291402
1 - 2 S^2 - S^4 A291403
1 - S^2 - 2 S^4 A291404
1 - 2 S^2 - 2 S^4 A291405
1 - S^3 - S^6 A291407
(1 - S)(1 - S^2) A291408
(1 - S^2)(1 - S)^2 A291409
1 - S - S^2 - 2 S^3 A291410
1 - 2 S - S^2 + S^3 A291411
1 - S - 2 S^2 + S^3 A291412
1 - 3 S + S^2 + S^3 A291413
1 - 2 S + S^3 A291414
1 - 3 S + S^2 A291415
1 - 4 S + S^2 A291416
1 - 4 S + 2 S^2 A291417

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = 1 - 2 s - s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291382 *)

Formula

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

A291728 p-INVERT of (1,0,1,0,0,0,0,...), where p(S) = 1 - S - S^2.

Original entry on oeis.org

1, 2, 4, 9, 17, 35, 70, 142, 285, 576, 1160, 2340, 4716, 9510, 19171, 38653, 77926, 157110, 316747, 638599, 1287479, 2595698, 5233196, 10550681, 21271280, 42885152, 86460984, 174314476, 351436368, 708532813, 1428476905, 2879960190, 5806303628, 11706120825
Offset: 0

Views

Author

Clark Kimberling, Sep 08 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 = (1,0,1,0,0,0,0,...) = A154272, in some cases t(1,0,1,0,0,0,0,...) is a shifted (or differently indexed) version of the indicated sequence:
***
p(S) t(1,0,1,0,0,0,0,...)
1 - S A000930 (Narayana's cows sequence)
1 - S^2 A002478 (except for 0's)
1 - S^3 A291723
1 - S^5 A291724
(1 - S)^2 A291725
(1 - S)^3 A291726
(1 - S)^4 A291727
1 - S - S^2 A291728
1 - 2S - S^2 A291729
1 - 2S - 2S^2 A291730
(1 - 2S)^2 A291732
(1 - S)(1 - 2S) A291734
1 - S - S^3 A291735
1 - S^2 - S^3 A291736
1 - S - S^2 - S^3 A291737
1 - S - S^4 A291738
1 - S^3 - S^6 A291739
(1 - S)(1 - S^2) A291740
(1 - S)(1 + S^2) A291741

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^3; p = 1 - s - s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A154272 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291728 *)

Formula

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

A290990 p-INVERT of the nonnegative integers (A000027), where p(S) = 1 - S - S^2.

Original entry on oeis.org

0, 1, 2, 5, 12, 28, 64, 145, 328, 743, 1686, 3830, 8704, 19781, 44950, 102133, 232048, 527208, 1197808, 2721421, 6183108, 14048151, 31917714, 72517738, 164761792, 374342057, 850512458, 1932380869, 4390407092, 9975090996, 22663602720, 51492150953
Offset: 0

Views

Author

Clark Kimberling, Aug 21 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).
See A290890 for a guide to related sequences.

Crossrefs

Programs

  • Magma
    I:=[0,1,2,5]; [n le 4 select I[n] else 4*Self(n-1) -5*Self(n-2) +2*Self(n-3) +Self(n-4): n in [1..50]]; // G. C. Greubel, Apr 12 2023
    
  • Mathematica
    z = 60; s = x^2/(1-x)^2; p = 1 -s -s^2;
    Drop[CoefficientList[Series[s, {x,0,z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x,0,z}], x], 1]  (* A290990 *)
    LinearRecurrence[{4,-5,2,1}, {0,1,2,5}, 50] (* G. C. Greubel, Apr 12 2023 *)
  • PARI
    concat(0, Vec(x*(1-2*x+2*x^2)/(1-4*x+5*x^2-2*x^3-x^4) + O(x^50))) \\ Colin Barker, Aug 24 2017
    
  • SageMath
    @CachedFunction
    def a(n): # a = A290990
        if (n<4): return (0,1,2,5)[n]
        else: return 4*a(n-1) -5*a(n-2) +2*a(n-3) +a(n-4)
    [a(n) for n in range(51)] # G. C. Greubel, Apr 12 2023

Formula

a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3) + a(n-4).
G.f.: x*(1 - 2*x + 2*x^2) / (1 - 4*x + 5*x^2 - 2*x^3 - x^4). - Colin Barker, Aug 24 2017

A289975 p-INVERT of the Fibonacci numbers (A000045, including 0), where p(S) = 1 - S - S^2.

Original entry on oeis.org

0, 1, 1, 4, 7, 18, 37, 85, 183, 407, 888, 1956, 4284, 9409, 20630, 45270, 99289, 217819, 477776, 1048053, 2298912, 5042783, 11061455, 24263687, 53223023, 116746272, 256086074, 561731936, 1232174181, 2702807740, 5928681960, 13004724921, 28526216361
Offset: 0

Views

Author

Clark Kimberling, Aug 21 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).
See A290890 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x^2/(1 - x - x^2); p = 1 - s - s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000045 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A289975 *)

Formula

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

A290991 p-INVERT of (0,0,1,2,3,4,5,...), the nonnegative integers A000027 preceded by one zero, where p(S) = 1 - S - S^2.

Original entry on oeis.org

0, 0, 1, 2, 3, 6, 13, 26, 50, 96, 184, 351, 669, 1278, 2447, 4692, 9004, 17285, 33182, 63687, 122208, 234461, 449774, 862776, 1655010, 3174766, 6090231, 11683285, 22413104, 42997349, 82486280, 158241688, 303570021, 582365698, 1117202719, 2143225358
Offset: 0

Views

Author

Clark Kimberling, Aug 21 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).
See A290890 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x^3/(1 - x)^2; p = 1 - s - s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* 0,0,1,2,3,4,5,... *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A290991 *)
  • PARI
    concat(vector(2), Vec(x^2*(1 - 2*x + x^2 + x^3) / (1 - 4*x + 6*x^2 - 5*x^3 + 3*x^4 - x^5 - x^6) + O(x^40))) \\ Colin Barker, Aug 24 2017

Formula

a(n) = 4*a(n-1) - 6*a(n-2) + 5*a(n-3) - 3*a(n-4) + a(n-5) + a(n-6).
G.f.: x^2*(1 - 2*x + x^2 + x^3) / (1 - 4*x + 6*x^2 - 5*x^3 + 3*x^4 - x^5 - x^6). - Colin Barker, Aug 24 2017

A113067 Expansion of -x/((x^2+x+1)*(x^2+3*x+1)); invert transform gives signed version of tetrahedral numbers A000292.

Original entry on oeis.org

0, -1, 4, -11, 28, -72, 188, -493, 1292, -3383, 8856, -23184, 60696, -158905, 416020, -1089155, 2851444, -7465176, 19544084, -51167077, 133957148, -350704367, 918155952, -2403763488, 6293134512, -16475640049, 43133785636, -112925716859, 295643364940, -774004377960
Offset: 0

Views

Author

Creighton Dement, Oct 13 2005

Keywords

Comments

Invert(a(n)) gives (0, -1, 4, -10, 20, -35, ...) = A000292 (with alternating signs).
Binomial(a(n)) gives (0, -1, 2, -2, 4, -7, 10, ...) = A094686 (with alternating signs, from 2nd term).
Floretion Algebra Multiplication Program, FAMP Code: 2basei[C*F]; C = - .5'j + .5'k - .5j' + .5k' - 'ii' - .5'ij' - .5'ik' - .5'ji' - .5'ki'; F = + .5'i + .5'ii' + .5'ij' + .5'ik'

References

  • Creighton Dement, Floretion Integer Sequences (work in progress).

Crossrefs

Programs

  • Mathematica
    -x/((x^2+x+1)*(x^2+3*x+1)) + O[x]^30 // CoefficientList[#, x]& (* Jean-François Alcover, Jun 15 2017 *)
  • PARI
    concat(0, Vec(-x / ((1 + x + x^2)*(1 + 3*x + x^2)) + O(x^30))) \\ Colin Barker, May 11 2019
  • SageMath
    [((lucas_number1(n,3,1)-lucas_number1(n,1,1)))/(-2) for n in range(1,32)] # Zerinvary Lajos, Jul 06 2008
    

Formula

a(n) + a(n+1) + a(n+2) = (-1)^n *A001906(n+2) = (-1)^n*F(2n+4).
a(n) + 3*a(n+1) + 3*a(n+2) + a(n+3) = ((-1)^(n+1))*A109961(n+2).
(|a(n)|) = A290890(n) for n >= 0, this being the p-INVERT of (1,2,3,4,...), where p(S) = 1 - S^2. - Clark Kimberling, Aug 21 2017
a(n) = -4*a(n-1) - 5*a(n-2) - 4*a(n-3) - a(n-4) for n > 3. - Colin Barker, May 11 2019
2*a(n) = (-1)^n*A001906(n+1) - A049347(n). - R. J. Mathar, Sep 20 2020

A289976 p-INVERT of (0,0,1,2,3,5,8,...), the Fibonacci numbers preceded by two zeros, where p(S) = 1 - S - S^2.

Original entry on oeis.org

0, 0, 1, 1, 2, 5, 9, 18, 36, 70, 137, 268, 522, 1017, 1980, 3852, 7492, 14568, 28321, 55051, 106999, 207952, 404134, 785366, 1526186, 2965752, 5763103, 11198858, 21761463, 42286357, 82169547, 159668921, 310262351, 602888757, 1171506956, 2276419286
Offset: 0

Views

Author

Clark Kimberling, Aug 21 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).
See A290890 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x^3/(1 - x - x^2); p = 1 - s - s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* 0,0,1,2,3,5,... *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A289976 *)

Formula

G.f.: ((1 - x)^2 x^2 (1 + x))/(1 - 2 x - x^2 + x^3 + 2 x^4 + x^5 - x^6).
a(n) = 2*a(n-1) + a(n-2) - a(n-3) - 2*a(n-4) - a(n-5) + a(n-6).

A290902 p-INVERT of the positive integers, where p(S) = 1 - 3*S.

Original entry on oeis.org

3, 15, 72, 345, 1653, 7920, 37947, 181815, 871128, 4173825, 19997997, 95816160, 459082803, 2199597855, 10538906472, 50494934505, 241935766053, 1159183895760, 5553983712747, 26610734667975, 127499689627128, 610887713467665, 2926938877711197, 14023806675088320
Offset: 0

Views

Author

Clark Kimberling, Aug 17 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).
See A290890 for a guide to related sequences.

Examples

			s = (1,2,3,4,...), p(S) = 1-3*S;
S(x) = x + 2 x^2 + 3 x^3 + ... ;
p(S(x)) = 1 - 3(x + 2 x^2 + 3 x^3 + ...);
1/p(S(x)) = 1 + 3 x + 15 x^2 + 72 x^3 + ... ;
(-p(0) + 1/p(S(x)))/x = 3 + 15 x + 72 x^2 + ... ;
t(s) = (3, 15, 72, ...), with offset 0.
		

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 3 s;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290902 *)
    u/3 (* A004254 shifted *)

Formula

G.f.: 3/(1 - 5 x + x^2).
a(n) = 5*a(n-1) - a(n-2).
a(n) = 3*A004254(n+1) for n >= 0.

A290903 p-INVERT of the positive integers, where p(S) = 1 - 5*S.

Original entry on oeis.org

5, 35, 240, 1645, 11275, 77280, 529685, 3630515, 24883920, 170556925, 1169014555, 8012544960, 54918800165, 376419056195, 2580014593200, 17683683096205, 121205767080235, 830756686465440, 5694091038177845, 39027880580779475, 267501073027278480
Offset: 0

Views

Author

Clark Kimberling, Aug 17 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).
See A290890 for a guide to related sequences.

Examples

			(See the example at A290902.)
		

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 5 s;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290903 *)
    u/5 (* A004187 shifted *)

Formula

G.f.: 5/(1 - 7 x + x^2).
a(n) = 7*a(n-1) - a(n-2).
a(n) = 5*A004187(n+1) for n >= 0.
Showing 1-10 of 64 results. Next