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.

Previous Showing 31-40 of 40 results.

A291411 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 2 S - S^2 + S^3.

Original entry on oeis.org

2, 7, 21, 63, 189, 567, 1699, 5092, 15260, 45731, 137046, 410697, 1230768, 3688339, 11053134, 33123790, 99264648, 297474121, 891463923, 2671519536, 8005951162, 23992058879, 71898875923, 215464974683, 645700711159, 1935021731510, 5798830691535, 17377808652745
Offset: 0

Views

Author

Clark Kimberling, Sep 07 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 A291382 for a guide to related sequences.

Crossrefs

Programs

  • GAP
    a:=[2,7,21,63,189,567];;  for n in [7..10^2] do a[n]:=2*a[n-1]+3*a[n-2]+a[n-3]-2*a[n-4]-3*a[n-5]-a[n-6]; od; a; # Muniru A Asiru, Sep 12 2017
  • Mathematica
    z = 60; s = x + x^2; p = 1 - 2 s - s^2 + s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291411 *)

Formula

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

A291412 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - S - 2 S^2 + S^3.

Original entry on oeis.org

1, 4, 10, 24, 62, 156, 391, 987, 2484, 6252, 15744, 39636, 99788, 251237, 632525, 1592480, 4009326, 10094104, 25413498, 63982496, 161086011, 405559431, 1021059816, 2570679048, 6472089792, 16294506424, 41023988824, 103284359545, 260034658537, 654678248796
Offset: 0

Views

Author

Clark Kimberling, Sep 07 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 A291382 for a guide to related sequences.

Crossrefs

Programs

  • GAP
    a:=[1,4,10,24,62,156];;  for n in [7..10^2] do a[n]:=a[n-1]+3*a[n-2]+3*a[n-3]-a[n-4]-3*a[n-5]-a[n-6]; od; a; # Muniru A Asiru, Sep 12 2017
  • Mathematica
    z = 60; s = x + x^2; p = 1 - s - 2 s^2 + s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291412 *)

Formula

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

A291413 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 3 S + S^2 + S^3.

Original entry on oeis.org

3, 11, 36, 117, 375, 1197, 3810, 12112, 38478, 122198, 388008, 1231911, 3911097, 12416751, 39419610, 125145175, 397296363, 1261288403, 4004182620, 12711979296, 40356397332, 128118414852, 406734209280, 1291248512101, 4099293000471, 13013918567075
Offset: 0

Views

Author

Clark Kimberling, Sep 07 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 A291382 for a guide to related sequences.

Crossrefs

Programs

  • GAP
    a:=[3,11,36,117,375,1197];;   for n in [7..10^3] do a[n]:=3*a[n-1]+
    2*a[n-2]-3*a[n-3]-4*a[n-4]-3*a[n-5]-a[n-6]; od; a; # Muniru A Asiru, Sep 12 2017
  • Mathematica
    z = 60; s = x + x^2; p = 1 - 3 s + s^2 + s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291413 *)

Formula

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

A291414 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 2 S + S^3.

Original entry on oeis.org

2, 6, 15, 37, 89, 212, 500, 1173, 2741, 6388, 14860, 34524, 80138, 185904, 431075, 999280, 2315960, 5366755, 12435075, 28810731, 66748062, 154635086, 358234115, 829886167, 1922494024, 4453566092, 10316878400, 23899399028, 55363614076, 128251081293
Offset: 0

Views

Author

Clark Kimberling, Sep 07 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 A291382 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = 1 - 2 s + s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291414 *)

Formula

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

A291415 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 3 S + S^2.

Original entry on oeis.org

3, 11, 37, 126, 427, 1448, 4909, 16643, 56424, 191292, 648529, 2198680, 7454090, 25271280, 85676131, 290464093, 984747891, 3338548317, 11318536416, 38372746007, 130093466328, 441050269849, 1495273713773, 5069362002354, 17186439428582, 58266444593059
Offset: 0

Views

Author

Clark Kimberling, Sep 07 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 A291382 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = 1 - 3 s + s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291415 *)

Formula

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

A291416 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 4 S + S^2.

Original entry on oeis.org

4, 19, 86, 392, 1784, 8121, 36966, 168267, 765940, 3486508, 15870352, 72240785, 328835240, 1496836103, 6813498210, 31014589884, 141176346720, 642625324009, 2925187658218, 13315259321575, 60610173266216, 275893470389144, 1255848695053856, 5716539585528849
Offset: 0

Views

Author

Clark Kimberling, Sep 07 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 A291382 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = 1 - 4 s + s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291416 *)

Formula

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

A291462 a(n) = (1/2)*A291417(n).

Original entry on oeis.org

2, 9, 38, 161, 680, 2872, 12128, 51214, 216264, 913228, 3856328, 16284284, 68764352, 290374208, 1226175744, 5177825416, 21864627616, 92328709904, 389880441696, 1646365025296, 6952176889728, 29357258422912, 123968166486528, 523485745182432, 2210545926231680
Offset: 0

Views

Author

Clark Kimberling, Sep 07 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = 1 - 4 s + 2 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291417 *)
    u / 2  (*A291462)

Formula

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

A291380 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - S^5.

Original entry on oeis.org

0, 0, 0, 0, 1, 5, 10, 10, 5, 2, 10, 45, 120, 210, 253, 225, 225, 500, 1375, 3005, 5025, 6625, 7575, 9850, 18508, 40150, 78275, 128375, 180625, 237888, 345090, 607105, 1163155, 2109140, 3426771, 5056055, 7237835, 11059960, 18816930, 33638409, 58293475
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).
See A291382 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = (1 - s)^5;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291380 *)

Formula

G.f.: -((x^4 (1 + x)^5)/((-1 + x + x^2) (1 + x + 2 x^2 + 3 x^3 + 5 x^4 + 7 x^5 + 7 x^6 + 4 x^7 + x^8))).
a(n) = a(n-5) + 5*a(n-6) + 10*a(n-7) + 10*a(n-8) + 5*a(n-9) + a(n-10) for n >= 11.

A291381 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - S^6.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 6, 15, 20, 15, 6, 2, 12, 66, 220, 495, 792, 925, 810, 648, 1036, 3126, 8580, 18566, 31848, 44034, 50644, 54384, 74328, 153161, 354702, 738966, 1312380, 1988814, 2638668, 3297933, 4531980, 7814811, 15621794, 30839391, 55350396, 88575614
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).
See A291382 for a guide to related sequences.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = (1 - s)^6;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291381 *)

Formula

G.f.: -((x^5 (1 + x)^6)/((-1 + x + x^2) (1 + x + x^2) (1 - x + 2 x^3 + x^4) (1 + x + 2 x^2 + 2 x^3 + x^4)))
a(n) = a(n-6) + 6*a(n-7) + 15*a(n-8) + 20*a(n-9) + 15*a(n-10) + 6*a(n-11) + a(n-12) for n >= 13.

A291386 a(n) = (1/3)*A099432(n+1).

Original entry on oeis.org

2, 11, 54, 252, 1134, 4977, 21438, 91017, 381996, 1588248, 6552252, 26853687, 109438938, 443837799, 1792373346, 7211142612, 28915704810, 115603540605, 460942202070, 1833459620517, 7276826042712, 28823185892016, 113957884236024, 449793742386627
Offset: 0

Views

Author

Clark Kimberling, Sep 04 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = (1 - 3 s)^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A099432 *)
    u / 3  (* A291386 *)
    LinearRecurrence[{6,-3,-18,-9},{2,11,54,252},30] (* Harvey P. Dale, Oct 06 2017 *)

Formula

G.f.: -(((1 + x) (-2 + 3 x + 3 x^2))/(-1 + 3 x + 3 x^2)^2).
a(n) = 6*a(n-1) - 3*a(n-2) - 18*a(n-3) - 9*a(n-4) for n >= 5.
Previous Showing 31-40 of 40 results.