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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A290917 p-INVERT of the positive integers, where p(S) = (1 - S)^2.

Original entry on oeis.org

2, 7, 22, 67, 200, 588, 1708, 4913, 14018, 39725, 111922, 313752, 875702, 2434747, 6746350, 18636343, 51340988, 141089508, 386857888, 1058572325, 2891193242, 7882921697, 21458980582, 58330331952, 158339542250, 429274563823, 1162435429318, 3144299295403
Offset: 0

Views

Author

Clark Kimberling, Aug 18 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/(1 - x)^2; p = (1 - s)^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A290917 *)
    LinearRecurrence[{6,-11,6,-1},{2,7,22,67},30] (* Harvey P. Dale, Jul 22 2024 *)
  • PARI
    Vec((2 - x)*(1 - 2*x) / (1 - 3*x + x^2)^2 + O(x^30)) \\ Colin Barker, Aug 24 2017

Formula

G.f.: (2 - 5 x + 2 x^2)/(1 - 3 x + x^2)^2.
a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4).
(a(n)) is the p-INVERT of (1,1,1,1,1...) using p(S) = (1 - S - S^2)^2.
a(n) = (((3-sqrt(5))/2)^n * (-3+sqrt(5)) * (-5+7*sqrt(5)-5*n) + 2^(-n) * (3+sqrt(5))^(n+1) * (5+7*sqrt(5)+5*n)) / 50. - Colin Barker, Aug 24 2017

A289977 p-INVERT of (0,0,0,1,2,3,5,8,...), the Fibonacci numbers preceded by three zeros, where p(S) = 1 - S - S^2.

Original entry on oeis.org

0, 0, 0, 1, 1, 2, 3, 7, 12, 23, 41, 77, 140, 258, 470, 861, 1570, 2867, 5225, 9526, 17352, 31607, 57547, 104766, 190684, 347029, 631476, 1148985, 2090427, 3803044, 6918379, 12585209, 22892932, 41641932, 75744383, 137772396, 250592150, 455792833, 829016539
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^4/(1 - x - x^2); p = 1 - s - s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* 0,0,0,1,2,3,5,... *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A289977 *)
    LinearRecurrence[{2,1,-2,0,-1,-1,0,1},{0,0,0,1,1,2,3,7},40] (* Harvey P. Dale, Jul 14 2018 *)
  • PARI
    concat(vector(3), Vec(x^3*(1 - x)*(1 - x^2 - x^3) / (1 - 2*x - x^2 + 2*x^3 + x^5 + x^6 - x^8) + O(x^50))) \\ Colin Barker, Aug 24 2017

Formula

a(n) = 2*a(n-1) + a(n-2) - 2*a(n-3) - a(n-5) - a(n-6) + a(n-8).
G.f.: x^3*(1 - x)*(1 - x^2 - x^3) / (1 - 2*x - x^2 + 2*x^3 + x^5 + x^6 - x^8). - Colin Barker, Aug 24 2017

A290900 p-INVERT of the positive integers, where p(S) = 1 - S^2 - S^3.

Original entry on oeis.org

0, 1, 5, 17, 51, 149, 439, 1308, 3916, 11728, 35093, 104943, 313773, 938199, 2805439, 8389163, 25086356, 75016104, 224321012, 670787533, 2005857561, 5998122649, 17936209267, 53634716681, 160384099011, 479597177352, 1434141243492, 4288517958652
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.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - s^2 - s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290900 *)
  • PARI
    concat(0, Vec(x*(1 - x + x^2) / (1 - 6*x + 14*x^2 - 19*x^3 + 14*x^4 - 6*x^5 + x^6) + O(x^40))) \\ Colin Barker, Aug 18 2017

Formula

a(n) = 6*a(n-1) - 14*a(n-2) + 19*a(n-3) - 14*a(n-4) + 6*a(n-5) - a(n-6).
G.f.: x*(1 - x + x^2) / (1 - 6*x + 14*x^2 - 19*x^3 + 14*x^4 - 6*x^5 + x^6). - Colin Barker, Aug 18 2017

A290904 p-INVERT of the positive integers, where p(S) = 1 - 2*S^2.

Original entry on oeis.org

0, 2, 8, 24, 72, 222, 688, 2128, 6576, 20322, 62808, 194120, 599960, 1854270, 5730912, 17712288, 54742624, 169190722, 522910632, 1616137848, 4994929128, 15437616926, 47712391952, 147462678768, 455756685840, 1408587979170, 4353463496440, 13455066133672
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.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 2 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290903 *)
    u/2 (* A290905 *)

Formula

G.f.: (2 x)/(1 - 4 x + 4 x^2 - 4 x^3 + x^4).
a(n) = 4*a(n-1) - 4*a(n-2) + 4*a(n-3) - a(n-4).
a(n) = 2*A290905(n) for n >= 0.

A290905 a(n) = (1/2)*A290904(n).

Original entry on oeis.org

0, 1, 4, 12, 36, 111, 344, 1064, 3288, 10161, 31404, 97060, 299980, 927135, 2865456, 8856144, 27371312, 84595361, 261455316, 808068924, 2497464564, 7718808463, 23856195976, 73731339384, 227878342920, 704293989585, 2176731748220, 6727533066836, 20792502889884
Offset: 0

Views

Author

Clark Kimberling, Aug 17 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 2 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290904 *)
    u/2 (* A290905 *)

Formula

G.f.: x/(1 - 4 x + 4 x^2 - 4 x^3 + x^4).
a(n) = 4*a(n-1) - 4*a(n-2) + 4*a(n-3) - a(n-4).
a(n) = (1/2)*A290904(n) for n >= 0.

A290906 p-INVERT of the positive integers, where p(S) = 1 - 3*S^2.

Original entry on oeis.org

0, 3, 12, 39, 132, 456, 1572, 5409, 18612, 64053, 220440, 758640, 2610840, 8985147, 30922188, 106418031, 366235308, 1260390744, 4337606988, 14927778921, 51373622388, 176801189997, 608457401520, 2093992746720, 7206429919920, 24800769855603, 85351303248012
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.

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 3 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290906 *)
    u/3 (* A290907 *)

Formula

G.f.: (3 x)/(1 - 4 x + 3 x^2 - 4 x^3 + x^4).
a(n) = 4*a(n-1) - 3*a(n-2) + 4*a(n-3) - a(n-4).
a(n) = 3*A290907(n) for n >= 0.

A290907 a(n) = (1/3)*A290906(n).

Original entry on oeis.org

0, 1, 4, 13, 44, 152, 524, 1803, 6204, 21351, 73480, 252880, 870280, 2995049, 10307396, 35472677, 122078436, 420130248, 1445868996, 4975926307, 17124540796, 58933729999, 202819133840, 697997582240, 2402143306640, 8266923285201, 28450434416004, 97911543452733
Offset: 0

Views

Author

Clark Kimberling, Aug 17 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 3 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290906 *)
    u/3 (* A290907 *)

Formula

G.f.: x/(1 - 4 x + 3 x^2 - 4 x^3 + x^4).
a(n) = 4*a(n-1) - 3*a(n-2) + 4*a(n-3) - a(n-4).
a(n) = (1/3)*A290906(n) for n >= 0.

A290909 p-INVERT of the positive integers, where p(S) = 1 - 5*S^2.

Original entry on oeis.org

0, 5, 20, 75, 300, 1200, 4780, 19045, 75900, 302475, 1205400, 4803680, 19143320, 76288725, 304020900, 1211564475, 4828248580, 19241224720, 76678887300, 305575754325, 1217760780300, 4852941691355, 19339630115120, 77071046136000, 307138560414000
Offset: 0

Views

Author

Clark Kimberling, Aug 18 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/(1 - x)^2; p = 1 - 5 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290909 *)
    u/5 (* A290910 *)

Formula

G.f.: (5 x)/(1 - 4 x + x^2 - 4 x^3 + x^4).
a(n) = 4*a(n-1) - a(n-2) + 4*a(n-3) - a(n-4).
a(n) = 5*A290910(n) for n >= 0.

A290910 a(n) = (1/5)*A290909(n), n>= 0.

Original entry on oeis.org

0, 1, 4, 15, 60, 240, 956, 3809, 15180, 60495, 241080, 960736, 3828664, 15257745, 60804180, 242312895, 965649716, 3848244944, 15335777460, 61115150865, 243552156060, 970588338271, 3867926023024, 15414209227200, 61427712082800, 244797754857825
Offset: 0

Views

Author

Clark Kimberling, Aug 18 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 5 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290909 *)
    u/5 (* A290910 *)
    LinearRecurrence[{4,-1,4,-1},{0,1,4,15},30] (* Harvey P. Dale, Feb 19 2018 *)
  • PARI
    concat([0], Vec(1/(1 - 4*x + x^2 - 4*x^3 + x^4) + O(x^30))) \\ Andrew Howroyd, Feb 26 2018

Formula

G.f.: x/(1 - 4 x + x^2 - 4 x^3 + x^4).
a(n) = 4*a(n-1) - a(n-2) + 4*a(n-3) - a(n-4).
a(n) = (1/5)*A290909(n) for n >= 0.

A290911 p-INVERT of the positive integers, where p(S) = 1 - 6*S^2.

Original entry on oeis.org

0, 6, 24, 96, 408, 1722, 7248, 30528, 128592, 541638, 2281416, 9609504, 40475976, 170487930, 718108320, 3024727680, 12740386464, 53663491206, 226034767224, 952075887072, 4010217126648, 16891344084282, 71147645118192, 299679373092288, 1262272651579632
Offset: 0

Views

Author

Clark Kimberling, Aug 18 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/(1 - x)^2; p = 1 - 6 s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A290911 *)
    u/6 (* A290912 *)

Formula

G.f.: (6 x)/(1 - 4 x - 4 x^3 + x^4).
a(n) = 4*a(n-1) + 4*a(n-3) - a(n-4).
a(n) = 6*A290912(n) for n >= 0.
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