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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A290929 p-INVERT of the positive integers, where p(S) = (1 - S)(1 - S^2).

Original entry on oeis.org

1, 4, 13, 39, 114, 330, 948, 2703, 7655, 21554, 60389, 168468, 468199, 1296826, 3581185, 9862749, 27096216, 74277342, 203200986, 554869701, 1512575195, 4116813032, 11188568267, 30367047720, 82316338381, 222875101936, 602784607477, 1628612506131
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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:=[1,4,13,39,114,330]; [n le 6 select I[n] else 7*Self(n-1)-18*Self(n-2)+23*Self(n-3)-18*Self(n-4)+7*Self(n-5)-Self(n-6): n in [1..40]]; // Vincenzo Librandi, Aug 20 2017
  • Mathematica
    z = 60; s = x/(1 - x)^2; p = (1 - s)(1 - s^2);
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A290929 *)
    LinearRecurrence[{7, -18, 23, -18, 7, -1}, {1, 4, 13, 39, 114, 330}, 40] (* Vincenzo Librandi, Aug 20 2017 *)
  • PARI
    Vec((1 - 3*x + 3*x^2 - 3*x^3 + x^4) / ((1 - 3*x + x^2)^2*(1 - x + x^2)) + O(x^30)) \\ Colin Barker, Aug 19 2017
    

Formula

a(n) = 7*a(n-1) - 18*a(n-2) + 23*a(n-3) - 18*a(n-4) + 7*a(n-5) - a(n-6).
G.f.: (1 - 3*x + 3*x^2 - 3*x^3 + x^4) / ((1 - 3*x + x^2)^2*(1 - x + x^2)). - Colin Barker, Aug 19 2017

A290930 p-INVERT of the positive integers, where p(S) = (1 - S^2)(1 - 2*S^2).

Original entry on oeis.org

0, 3, 12, 37, 116, 372, 1188, 3763, 11860, 37261, 116760, 365056, 1139224, 3549635, 11045804, 34335421, 106633804, 330916268, 1026277180, 3181108619, 9855901108, 30524529485, 94506627952, 292521594048, 905220237168, 2800700318291, 8663793207244
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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)(1 - 2s^2);
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A290930 *)

Formula

G.f.: (3 x - 12 x^2 + 16 x^3 - 12 x^4 + 3 x^5)/(1 - 8 x + 25 x^2 - 44 x^3 + 54 x^4 - 44 x^5 + 25 x^6 - 8 x^7 + x^8).
a(n) = 8*a(n-1) - 25*a(n-2) + 44*a(n-3) - 54*a(n-4) + 44*a(n-5) - 25*a(n-6) + 8*a(n-7) - a(n-8).

A291025 p-INVERT of the positive integers, where p(S) = 1 - 3*S + S^2.

Original entry on oeis.org

3, 14, 62, 273, 1200, 5271, 23146, 101626, 446181, 1958880, 8600043, 37756502, 165760934, 727733433, 3194937360, 14026596927, 61580365906, 270353629378, 1186921889997, 5210892012480, 22877154557139, 100436585338334, 440942410322894, 1935850452749409
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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 + s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291025 *)
    LinearRecurrence[{7,-13,7,-1},{3,14,62,273},30] (* Harvey P. Dale, Jun 22 2022 *)

Formula

G.f.: (3 - 7 x + 3 x^2)/(1 - 7 x + 13 x^2 - 7 x^3 + x^4).
a(n) = 7*a(n-1) - 13*a(n-2) + 7*a(n-3) - a(n-4).

A291026 p-INVERT of the positive integers, where p(S) = 1 - 4*S + S^2.

Original entry on oeis.org

4, 23, 128, 711, 3948, 21920, 121700, 675673, 3751296, 20826953, 115629868, 641969344, 3564171060, 19788040311, 109861881472, 609945846247, 3386378699324, 18800948912352, 104381615697460, 579519775642745, 3217455182279552, 17863096800262569
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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 - 4 s + s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291026 *)
    LinearRecurrence[{8,-15,8,-1},{4,23,128,711},30] (* Harvey P. Dale, May 18 2024 *)

Formula

G.f.: (4 - 9 x + 4 x^2)/(1 - 8 x + 15 x^2 - 8 x^3 + x^4).
a(n) = 8*a(n-1) - 15*a(n-2) + 8*a(n-3) - a(n-4).

A291027 p-INVERT of the positive integers, where p(S) = 1 - 5*S + S^2.

Original entry on oeis.org

5, 34, 226, 1501, 9968, 66195, 439582, 2919134, 19385099, 128730656, 854861845, 5676882210, 37698479330, 250344342349, 1662462010576, 11039913707011, 73312769785118, 486848208799710, 3233013554202907, 21469477452590144, 142572387761274149, 946780646936461346
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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 + s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291027 *)

Formula

G.f.: (5 - 11 x + 5 x^2)/(1 - 9 x + 17 x^2 - 9 x^3 + x^4).
a(n) = 9*a(n-1) - 17*a(n-2) + 9*a(n-3) - a(n-4).

A291028 p-INVERT of the positive integers, where p(S) = 1 - 6*S + S^2.

Original entry on oeis.org

6, 47, 362, 2787, 21456, 165180, 1271644, 9789793, 75367038, 580215573, 4466808294, 34387867640, 264736107506, 2038079457267, 15690220398162, 120791667500967, 929918545909756, 7159007901103540, 55113853093361544, 424295774604244773, 3266454697733704038
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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:=[6,47,362,2787]; [n le 4 select I[n] else 10*Self(n-1)-19*Self(n-2)+10*Self(n-3)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Aug 20 2017
  • Mathematica
    z = 60; s = x/(1 - x)^2; p = 1 - 6 s + s^2;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291028 *)
    LinearRecurrence[{10, -19, 10, -1}, {6, 47, 362, 2787}, 40] (* Vincenzo Librandi, Aug 20 2017 *)

Formula

G.f.: (6 - 13 x + 6 x^2)/(1 - 10 x + 19 x^2 - 10 x^3 + x^4).
a(n) = 10*a(n-1) - 19*a(n-2) + 10*a(n-3) - a(n-4).

A291029 p-INVERT of the positive integers, where p(S) = 1 - S - S^2 - S^3.

Original entry on oeis.org

1, 4, 15, 55, 198, 706, 2510, 8923, 31737, 112918, 401799, 1429744, 5087461, 18102522, 64413263, 229198253, 815544198, 2901909494, 10325718678, 36741486569, 130735386073, 465189151460, 1655259161187, 5889825416864, 20957469541173, 74571909803996
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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 - s^2 - s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291029 *)

Formula

G.f.: (1 - 3 x + 5 x^2 - 3 x^3 + x^4)/(1 - 7 x + 18 x^2 - 25 x^3 + 18 x^4 - 7 x^5 + x^6).
a(n) = 7*a(n-1) - 18*a(n-2) + 25*a(n-3) - 18*a(n-4) + 7*a(n-5) - a(n-6).

A291031 p-INVERT of the positive integers, where p(S) = 1 - 3*S + 2*S^3.

Original entry on oeis.org

3, 15, 70, 321, 1461, 6624, 29967, 135399, 611318, 2758881, 12447753, 56154744, 253306119, 1142572767, 5153589754, 23244956169, 104843981505, 472885383744, 2132882300571, 9620044596687, 43389716584682, 195702453488433, 882684641446989, 3981207177094608
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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 s^3;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291031 *)

Formula

G.f.: (3 - 12 x + 16 x^2 - 12 x^3 + 3 x^4)/(1 - 9 x + 27 x^2 - 36 x^3 + 27 x^4 - 9 x^5 + x^6).
a(n) = 9*a(n-1) - 27*a(n-2) + 36*a(n-3) - 27*a(n-4) + 90*a(n-5) - a(n-6).

A291032 p-INVERT of the positive integers, where p(S) = 1 - S - S^2 - S^3 + S^4.

Original entry on oeis.org

1, 4, 15, 54, 188, 645, 2208, 7570, 25982, 89190, 306095, 1050268, 3603276, 12361763, 42409154, 145491117, 499126660, 1712311759, 5874263702, 20152234481, 69134134820, 237171010852, 813636681973, 2791253840066, 9575645985794, 32850107071454, 112695214040224
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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 - s^2 - s^3 + s^4;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291032 *)

Formula

G.f.: (1 - 5 x + 12 x^2 - 17 x^3 + 12 x^4 - 5 x^5 + x^6)/(1 - 9 x + 33 x^2 - 68 x^3 + 87 x^4 - 68 x^5 + 33 x^6 - 9 x^7 + x^8).
a(n) = 9*a(n-1) - 33*a(n-2) + 68*a(n-3) - 87*a(n-4) + 68*a(n-5) - 33*a(n-6) + 9*a(n-7) - a(n-8).

A291034 p-INVERT of the positive integers, where p(S) = 1 - 7*S.

Original entry on oeis.org

7, 63, 560, 4977, 44233, 393120, 3493847, 31051503, 275969680, 2452675617, 21798110873, 193730322240, 1721774789287, 15302242781343, 135998410242800, 1208683449403857, 10742152634391913, 95470690260123360, 848494059706718327, 7540975847100341583
Offset: 0

Views

Author

Clark Kimberling, Aug 19 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 - 7 s;
    Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000027 *)
    Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1]  (* A291034 *)

Formula

G.f.: 7/(1 - 9 x + x^2).
a(n) = 9*a(n-1) - a(n-2).
a(n) = 7*A018913(n) for n >= 1.
Previous Showing 51-60 of 64 results. Next