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 40 results. Next

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.

A291383 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 2 S - 2 S^2.

Original entry on oeis.org

2, 8, 28, 98, 344, 1208, 4240, 14884, 52248, 183408, 643824, 2260040, 7933504, 27849280, 97760384, 343171984, 1204649632, 4228727296, 14844261824, 52108375328, 182918006400, 642104016000, 2254002082560, 7912309005376, 27774878417792, 97499209219328
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 - 2 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]  (* A291383 *)
    u / 2  (* A291384 *)

Formula

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

A291387 p-INVERT of (1,1,0,0,0,0,...), where p(S) = (1 - 4 S)^2.

Original entry on oeis.org

8, 56, 352, 2096, 12032, 67328, 369664, 2000128, 10696704, 56666112, 297836544, 1555066880, 8073379840, 41709076480, 214558048256, 1099562549248, 5616171483136, 28599668703232, 145249047412736, 735884541427712, 3720035809886208, 18767645931208704
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.
All terms = 0 mod 8. - Muniru A Asiru, Sep 07 2017

Crossrefs

Programs

  • GAP
    a:=8*[1,7,44,262];; for n in [5..10^2] do a[n]:=8*a[n-1]-8*a[n-2]-32*a[n-3]-16*a[n-4]; od; a;  # Muniru A Asiru, Sep 07 2017
  • Mathematica
    z = 60; s = x + x^2; p = (1 - 4 s)^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291387 *)
    u / 8  (* A291388 *)

Formula

G.f.: -((8 (1 + x) (-1 + 2 x + 2 x^2))/(-1 + 4 x + 4 x^2)^2).
a(n) = 8*a(n-1) - 8*a(n-2) - 32*a(n-3) - 16*a(n-4) for n >= 5.

A291389 p-INVERT of (1,1,0,0,0,0,...), where p(S) = (1 - 5 S)^2.

Original entry on oeis.org

10, 85, 650, 4700, 32750, 222375, 1481250, 9721875, 63062500, 405175000, 2582687500, 16353078125, 102955156250, 644991640625, 4023367968750, 25002220312500, 154848222656250, 956155732421875, 5888138769531250, 36171585068359375, 221714776953125000
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.
All terms = 0 mod 5. - Muniru A Asiru, Sep 07 2017

Crossrefs

Programs

  • GAP
    a:=5*[2,17,130,940];; for n in [5..10^2] do a[n]:=10*a[n-1]-15*a[n-2]-50*a[n-3]-25*a[n-4]; od; a;  # Muniru A Asiru, Sep 07 2017
  • Mathematica
    z = 60; s = x + x^2; p = (1 - 5 s)^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291389 *)
    u / 5  (* A291390 *)

Formula

G.f.: -((5 (1 + x) (-2 + 5 x + 5 x^2))/(-1 + 5 x + 5 x^2)^2).
a(n) = 10*a(n-1) - 15*a(n-2) - 50*a(n-3) - 25*a(n-4) for n >= 5.

A291391 p-INVERT of (1,1,0,0,0,0,...), where p(S) = (1 - 6 S)^2.

Original entry on oeis.org

12, 120, 1080, 9180, 75168, 599616, 4691520, 36164880, 275503680, 2078711424, 15559682688, 115688917440, 855249269760, 6291326453760, 46080184338432, 336227628720384, 2445042642140160, 17726787591690240, 128173151784867840, 924487654349822976
Offset: 0

Views

Author

Clark Kimberling, Sep 06 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 - 6 s)^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291391 *)
    u / 12  (* A291392 *)

Formula

G.f.: -((12 (1 + x) (-1 + 3 x + 3 x^2))/(-1 + 6 x + 6 x^2)^2).
a(n) = 12*a(n-1) - 24*a(n-2) - 72*a(n-3) - 36*a(n-4) for n >= 5.

A291405 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 2 S^2 - 2 S^4.

Original entry on oeis.org

0, 2, 4, 8, 24, 52, 120, 290, 672, 1592, 3760, 8824, 20800, 48976, 115296, 271588, 639488, 1505816, 3546032, 8350064, 19662944, 46302800, 109033952, 256754760, 604609280, 1423740736, 3352643712, 7894846528, 18590881280, 43778039424, 103089066752
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^2 - 2 s^4;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291405 *)
    u / 2 (* A291406 *)

Formula

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

A291408 p-INVERT of (1,1,0,0,0,0,...), where p(S) = (1 - S)(1 - S^2).

Original entry on oeis.org

1, 3, 6, 11, 21, 39, 70, 126, 224, 394, 690, 1201, 2079, 3585, 6158, 10541, 17991, 30623, 51996, 88092, 148944, 251364, 423492, 712369, 1196557, 2007135, 3362598, 5626847, 9405465, 15705447, 26200066, 43667802, 72719312, 121000846, 201185334, 334265089
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:=[1,3,6,11,21,39];;
    for n in [7..10^2] do a[n]:=a[n-1]+2*a[n-2]+a[n-3]-2*a[n-4]-3*a[n-5]- a[n-6]; od; a; # Muniru A Asiru, Sep 10 2017
  • Mathematica
    z = 60; s = x + x^2; p = (1 - s)(1 - s^2);
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291408 *)

Formula

G.f.: -(((1 + x) (-1 - x + 2 x^3 + x^4))/((-1 + x + x^2)^2 (1 + x + x^2))).
a(n) = a(n-1) + 2*a(n-2) + a(n-3) - 2*a(n-4) - 3*a(n-5) - a(n-6) for n >= 7.
a(n) = (1/2) * A275439(n+4). - Alois P. Heinz, May 20 2025

A291417 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 4 S + 2 S^2.

Original entry on oeis.org

4, 18, 76, 322, 1360, 5744, 24256, 102428, 432528, 1826456, 7712656, 32568568, 137528704, 580748416, 2452351488, 10355650832, 43729255232, 184657419808, 779760883392, 3292730050592, 13904353779456, 58714516845824, 247936332973056, 1046971490364864
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 + 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.: -((2 (-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.

A291379 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - S^4.

Original entry on oeis.org

0, 0, 0, 1, 4, 6, 4, 2, 8, 28, 56, 71, 68, 94, 228, 497, 808, 1044, 1352, 2316, 4608, 8264, 12592, 17717, 26968, 47044, 83912, 138417, 211052, 319850, 517356, 881918, 1483336, 2377252, 3700648, 5853067, 9605596, 15991378, 26154700, 41734433, 66214096
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)^4;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1]  (* A019590 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291379 *)

Formula

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

A291384 a(n) = (1/2)*A291383(n).

Original entry on oeis.org

1, 4, 14, 49, 172, 604, 2120, 7442, 26124, 91704, 321912, 1130020, 3966752, 13924640, 48880192, 171585992, 602324816, 2114363648, 7422130912, 26054187664, 91459003200, 321052008000, 1127001041280, 3956154502688, 13887439208896, 48749604609664
Offset: 0

Views

Author

Clark Kimberling, Sep 04 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 60; s = x + x^2; p = 1 - 2 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]  (* A291383 *)
    u / 2  (* A291384 *)

Formula

G.f.: -(((1 + x) (1 + x + x^2))/(-1 + 2 x + 4 x^2 + 4 x^3 + 2 x^4))
a(n) = 2*a(n-1) + 4*a(n-2) + 4*a(n-3) + 2*a(n-4) for n >= 5.
Showing 1-10 of 40 results. Next