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 1-6 of 6 results.

A147607 Expansion of g.f.: 1/((1 - 2*x^2 + x^4 + 2*x^6 - x^8)*(1 - 2*x^2 - x^4 + 2*x^6 - x^8)).

Original entry on oeis.org

1, 0, 4, 0, 12, 0, 28, 0, 59, 0, 116, 0, 228, 0, 460, 0, 968, 0, 2092, 0, 4564, 0, 9908, 0, 21309, 0, 45444, 0, 96484, 0, 204700, 0, 434999, 0, 926440, 0, 1976344, 0, 4218936, 0, 9005328, 0, 19212728, 0, 40970200, 0, 87341032, 0, 186180665, 0, 396899620
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 60); Coefficients(R!( 1/((1-2*x^2+x^4 +2*x^6-x^8)*(1-2*x^2-x^4+2*x^6-x^8)) )); // G. C. Greubel, Oct 24 2022
    
  • Mathematica
    CoefficientList[Series[1/(1-4 x^2+4 x^4+4 x^6-11 x^8+4 x^10+4 x^12-4 x^14+x^16),{x,0,60}],x] (* or *) LinearRecurrence[ {0,4,0,-4,0,-4,0,11,0,-4,0,-4,0,4,0,-1},{1,0,4,0,12,0,28,0,59,0,116,0,228,0,460,0},60] (* Harvey P. Dale, Apr 03 2013 *)
  • SageMath
    def A147607_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1-2*x^2+x^4+2*x^6-x^8)*(1-2*x^2-x^4+2*x^6-x^8)) ).list()
    A147607_list(60) # G. C. Greubel, Oct 24 2022

Formula

G.f.: 1/(1 - 4*x^2 + 4*x^4 + 4*x^6 - 11*x^8 + 4*x^10 + 4*x^12 - 4*x^14 + x^16).
a(n) = 4*a(n-2) - 4*a(n-4) - 4*a(n-6) + 11*a(n-8) - 4*a(n-10) - 4*a(n-12) + 4*a(n-14) - a(n-16) with a(0)=1, a(1)=0, a(2)=4, a(3)=0, a(4)=12, a(5)=0, a(6)=28, a(7)=0, a(8)=59, a(9)=0, a(10)=116, a(11)=0, a(12)=228, a(13)=0, a(14)=460, a(15)=0. - Harvey P. Dale, Apr 03 2013
G.f.: -1/(x^8*f(x)*f(1/x)), where f(x) = -1 + 2*x^2 - x^4 - 2*x^6 + x^8. - G. C. Greubel, Oct 24 2022

Extensions

Definition corrected by N. J. A. Sloane, Nov 09 2008

A147606 Expansion of g.f.: 1/((1 - x - x^2 + x^4 - x^6)*(1 - x^2 + x^4 + x^5 - x^6)).

Original entry on oeis.org

1, 1, 3, 4, 6, 8, 12, 15, 25, 35, 56, 84, 130, 192, 294, 432, 654, 972, 1466, 2192, 3308, 4953, 7463, 11185, 16820, 25224, 37906, 56868, 85445, 128239, 192643, 289196, 434364, 652124, 979372, 1470436, 2208192, 3315556, 4978892, 7475948, 11226252
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/((1-x-x^2+x^4-x^6)*(1-x^2+x^4+x^5-x^6)) )); // G. C. Greubel, Oct 24 2022
    
  • Mathematica
    f[x_]= -1+x+x^2-x^4+x^6;
    CoefficientList[Series[-1/(x^6*f[x]*f[1/x]), {x, 0, 50}], x] (* G. C. Greubel, Oct 24 2022 *)
  • SageMath
    def A147606_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1-x-x^2+x^4-x^6)*(1-x^2+x^4+x^5-x^6)) ).list()
    A147606_list(50) # G. C. Greubel, Oct 24 2022

Formula

G.f.: 1/(1 - x - 2*x^2 + x^3 + 3*x^4 - 5*x^6 + 3*x^8 + x^9 - 2*x^10 - x^11 + x^12).
G.f.: -1/(x^6*f(x)*f(1/x)), where f(x) = -1 + x + x^2 - x^4 + x^6. - G. C. Greubel, Oct 24 2022

Extensions

Definition corrected by N. J. A. Sloane, Nov 09 2008

A147605 Expansion of g.f.: 1/((1 - x^2 - x^3 - x^4 - x^5 - x^6 - x^7)*(1 + x + x^2 + x^3 + x^4 + x^5 - x^7)).

Original entry on oeis.org

1, -1, 1, 0, 1, 1, 3, 3, 3, 10, 11, 21, 32, 52, 77, 128, 206, 320, 517, 817, 1297, 2060, 3290, 5220, 8298, 13205, 20980, 33360, 53056, 84366, 134114, 213263, 339086, 539123, 857240, 1363034, 2167197, 3445840, 5478951, 8711511, 13851359
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/((1-x^2-x^3-x^4-x^5-x^6-x^7)*(1+x+x^2+x^3+x^4+x^5-x^7)) )); // G. C. Greubel, Oct 24 2022
    
  • Mathematica
    f[x_]= -1 +x^2 +x^3 +x^4 +x^5 +x^6 +x^7;
    CoefficientList[Series[-1/(x^7*f[x]*f[1/x]), {x,0,50}], x] (* G. C. Greubel, Oct 24 2022 *)
  • PARI
    Vec(1/(1 +x -x^3 -2*x^4 -3*x^5 -5*x^6 -7*x^7 -5*x^8 -3*x^9 -2*x^10 -x^11 + x^13 +x^14) + O(x^40)) \\ Jinyuan Wang, Mar 10 2020
    
  • SageMath
    def A147605_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1-x^2-x^3-x^4-x^5-x^6-x^7)*(1+x+x^2+x^3+x^4+x^5-x^7)) ).list()
    A147605_list(50) # G. C. Greubel, Oct 24 2022

Formula

G.f.: 1/(1 + x - x^3 - 2*x^4 - 3*x^5 - 5*x^6 - 7*x^7 - 5*x^8 - 3*x^9 - 2*x^10 - x^11 + x^13 + x^14).
G.f.: -1/(x^7*f(x)*f(1/x)), where f(x) = -1 + x^2 + x^3 + x^4 + x^5 + x^6 + x^7. - G. C. Greubel, Oct 24 2022

Extensions

Definition corrected by N. J. A. Sloane, Nov 09 2008

A147620 Expansion of g.f.: 1/((1 - x - x^2 + x^6 - x^8)*(1 - x^2 + x^6 + x^7 - x^8)).

Original entry on oeis.org

1, 1, 3, 4, 8, 12, 19, 29, 46, 70, 111, 170, 271, 422, 668, 1048, 1655, 2603, 4104, 6453, 10167, 15989, 25175, 39599, 62329, 98064, 154335, 242845, 382183, 601399, 946451, 1489366, 2343847, 3688412, 5804459, 9134287, 14374533, 22620800, 35597998
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/((1-x-x^2+x^6- x^8)*(1-x^2+x^6+x^7-x^8)) )); // G. C. Greubel, Oct 24 2022
    
  • Mathematica
    f[x_]= -1+x^2-x^6-x^7+x^8;
    CoefficientList[Series[-1/(x^8*f[x]*f[1/x]), {x, 0, 50}], x]
  • PARI
    Vec(1/(1-x-2*x^2+x^3+x^4+2*x^6-5*x^8+2*x^10+x^12+x^13-2*x^14-x^15+x^16) + O(x^40)) \\ Jinyuan Wang, Mar 10 2020
    
  • SageMath
    def A147620_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1-x-x^2+x^6-x^8)*(1-x^2+x^6+x^7-x^8)) ).list()
    A147620_list(40) # G. C. Greubel, Oct 24 2022

Formula

G.f.: 1/(1 - x - 2*x^2 + x^3 + x^4 + 2*x^6 - 5*x^8 + 2*x^10 + x^12 + x^13 - 2*x^14 - x^15 + x^16).

Extensions

Definition corrected by N. J. A. Sloane, Nov 09 2008

A147598 Expansion of g.f. 1/((1-x^2+x^3+x^4-x^5)*(1-x-x^2+x^3-x^5)).

Original entry on oeis.org

1, 1, 3, 2, 4, 3, 6, 9, 14, 23, 29, 45, 57, 88, 123, 184, 267, 382, 556, 787, 1149, 1643, 2392, 3444, 4978, 7184, 10348, 14956, 21550, 31152, 44924, 64881, 93611, 135101, 195000, 281382, 406201, 586164, 846121, 1221064, 1762399, 2543555, 3671003
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/((1-x^2+x^3+x^4-x^5)*(1-x-x^2+x^3-x^5)) )); // G. C. Greubel, Oct 25 2022
    
  • Mathematica
    f[x_]= x^5 -x^4 -x^3 +x^2 -1;
    CoefficientList[Series[-1/(x^5*f[x]*f[1/x]), {x,0,50}],x]
  • SageMath
    def A147598_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1-x^2+x^3+x^4-x^5)*(1-x-x^2+x^3-x^5)) ).list()
    A147598_list(50) # G. C. Greubel, Oct 25 2022

Formula

G.f.: -1/(x^5*f(x)*f(1/x)), where f(x) = -1 +x^2 -x^3 -x^4 +x^5.
G.f.: 1/((x^5-x^4-x^3+x^2-1)*(x^5-x^3+x^2+x-1)). - Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009

Extensions

Better name (using g.f.) from Joerg Arndt, Apr 06 2018

A147593 Expansion of 1/(1 - x + x^3 - 3*x^4 + x^5 - x^7 + x^8).

Original entry on oeis.org

1, 1, 1, 0, 2, 3, 5, 3, 6, 8, 16, 16, 24, 28, 50, 61, 91, 109, 170, 220, 327, 415, 607, 800, 1164, 1536, 2192, 2928, 4172, 5616, 7921, 10705, 15049, 20460, 28638, 39027, 54453, 74451, 103662, 141996, 197288, 270704, 375632, 516096, 715258, 983661, 1362091
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/((1+x^3-x^4)*(1-x-x^4)) )); // G. C. Greubel, Oct 25 2022
    
  • Mathematica
    f[x_]= x^4-x^3-1; CoefficientList[Series[-1/(x^4*f[x]*f[1/x]), {x,0,50}], x]
  • SageMath
    def A147593_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1+x^3-x^4)*(1-x-x^4)) ).list()
    A147593_list(50) # G. C. Greubel, Oct 25 2022

Formula

G.f.: -1/(x^4*f(x)*f(1/x)), where f(x) = -1 - x^3 + x^4.
G.f.: 1/((1+x^3-x^4)*(1-x-x^4)). - Colin Barker, Nov 04 2012

Extensions

Edited by Joerg Arndt and Colin Barker, Nov 04 2012.
Showing 1-6 of 6 results.