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 1-4 of 4 results.

A101386 Expansion of g.f.: (5 - 3*x)/(1 - 6*x + x^2).

Original entry on oeis.org

5, 27, 157, 915, 5333, 31083, 181165, 1055907, 6154277, 35869755, 209064253, 1218515763, 7102030325, 41393666187, 241259966797, 1406166134595, 8195736840773, 47768254910043, 278413792619485, 1622714500806867, 9457873212221717, 55124524772523435, 321289275422918893
Offset: 0

Views

Author

Creighton Dement, Jan 23 2005

Keywords

Comments

A floretion-generated sequence relating to NSW numbers and numbers n such that (n^2 - 8)/2 is a square. It is also possible to label this sequence as the "tesfor-transform of the zero-sequence" under the floretion given in the program code, below. This is because the sequence "vesseq" would normally have been A046184 (indices of octagonal numbers which are also a square) using the floretion given. This floretion, however, was purposely "altered" in such a way that the sequence "vesseq" would turn into A000004. As (a(n)) would not have occurred under "natural" circumstances, one could speak of it as the transform of A000004.
Floretion Algebra Multiplication Program FAMP code: - tesforseq[ + 3'i - 2'j + 'k + 3i' - 2j' + k' - 4'ii' - 3'jj' + 4'kk' - 'ij' - 'ji' + 3'jk' + 3'kj' + 4e], Note: vesforseq = A000004, lesforseq = A002315, jesforseq = A077445
From Wolfdieter Lang, Feb 05 2015: (Start)
All positive solutions x = a(n) of the (generalized) Pell equation x^2 - 2*y^2 = +7 based on the fundamental solution (x2,y2) = (5,3) of the second class of (proper) solutions. The corresponding y solutions are given by y(n) = A253811(n).
All other positive solutions come from the first class of (proper) solutions based on the fundamental solution (x1,y1) = (3,1). These are given in A038762 and A038761.
All solutions of this Pell equation are found in A077443(n+1) and A077442(n), for n >= 0. See, e.g., the Nagell reference on how to find all solutions.
(End)

References

  • T. Nagell, Introduction to Number Theory, Chelsea Publishing Company, 1964, Theorem 109, pp. 207-208 with Theorem 104, pp. 197-198.

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 30); Coefficients(R!((5 - 3*x)/(1-6*x+x^2))); // G. C. Greubel, Jul 26 2018
    
  • Maple
    A101386:= (n) -> simplify(5*ChebyshevU(n, 3) - 3*ChebyshevU(n-1, 3)); seq( A101386(n), n = 0..30); # G. C. Greubel, Mar 17 2020
  • Mathematica
    CoefficientList[ Series[(5-3x)/(1-6x+x^2), {x,0,30}], x] (* Robert G. Wilson v, Jan 29 2005 *)
    LinearRecurrence[{6,-1},{5,27},30] (* Harvey P. Dale, Apr 23 2016 *)
  • PARI
    Vec((5-3*x)/(1-6*x+x^2) + O(x^30)) \\ Colin Barker, Feb 05 2015
    
  • SageMath
    [5*chebyshev_U(n,3) -3*chebyshev_U(n-1,3) for n in (0..30)] # G. C. Greubel, Mar 17 2020

Formula

a(n) = A002315(n) + A077445(n+1). Note: the offset of A077445 is 1.
a(n+1) - a(n) = 2*A054490(n+1).
a(n) = 6*a(n-1) - a(n-2), a(0)=5, a(1)=27. - Philippe Deléham, Nov 17 2008
From Al Hakanson (hawkuu(AT)gmail.com), Aug 17 2009: (Start)
a(n) = ((5+sqrt(18))*(3 + sqrt(8))^n + (5-sqrt(18))*(3 - sqrt(8))^n)/2.
Third binomial transform of A164737. (End)
a(n) = rational part of z(n), with z(n) = (5+3*sqrt(2))*(3+2*sqrt(2))^n, n >= 0, the general positive solutions of the second class of proper solutions. See the preceding formula. - Wolfdieter Lang, Feb 05 2015
a(n) = 5*A001109(n+1) - 3*A001109(n). - G. C. Greubel, Mar 17 2020
a(n) = Pell(2*n+2) + 3*Pell(2*n+1), where Pell(n) = A000129(n). - G. C. Greubel, Apr 17 2020
E.g.f.: exp(3*x)*(5*cosh(2*sqrt(2)*x) + 3*sqrt(2)*sinh(2*sqrt(2)*x)). - Stefano Spezia, Mar 16 2024

Extensions

More terms from Robert G. Wilson v, Jan 29 2005

A164593 a(n) = ((5 + sqrt(18))*(2 + sqrt(8))^n + (5 - sqrt(18))*(2 - sqrt(8))^n)/2.

Original entry on oeis.org

5, 22, 108, 520, 2512, 12128, 58560, 282752, 1365248, 6592000, 31828992, 153683968, 742051840, 3582943232, 17299980288, 83531694080, 403326697472, 1947433566208, 9403041054720, 45401898483712, 219219758153728, 1058486626549760, 5110825538813952, 24677248661454848
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 17 2009

Keywords

Comments

Binomial transform of A096980 without initial 1. Second binomial transform of A164737. Inverse binomial transform of A101386.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((5+3*r)*(2+2*r)^n+(5-3*r)*(2-2*r)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 24 2009
    
  • Maple
    seq(coeff(series( (5+2*x)/(1-4*x-4*x^2) , x, n+1), x, n), n = 0..25); # G. C. Greubel, Apr 16 2020
  • Mathematica
    LinearRecurrence[{4, 4}, {5, 22}, 25] (* G. C. Greubel, Aug 12 2017 *)
    Table[2^n*(Fibonacci[n+2, 2] + 3*Fibonacci[n+1, 2]), {n,0,25}] (* G. C. Greubel, Apr 16 2020 *)
  • PARI
    my(x='x+O('x^25)); Vec((5+2*x)/(1-4*x-4*x^2)) \\ G. C. Greubel, Aug 12 2017
    
  • Sage
    [2^n*(lucas_number1(n+2, 2, -1) + 3*lucas_number1(n+1, 2, -1)) for n in range(25)] # G. C. Greubel, Apr 16 2020

Formula

a(n) = 4*a(n-1) + 4*a(n-2) for n > 1; a(0) = 5, a(1) = 22.
G.f.: (5 + 2*x)/(1-4*x-4*x^2).
E.g.f.: exp(2*x)*(5*cosh(2*sqrt(2)*x) + 3*sqrt(2)*sinh(2*sqrt(2)*x)). - G. C. Greubel, Aug 12 2017
a(n) = 2^n*(Pell(n+2) + 3*Pell(n+1)), where Pell(n) = A000129(n). - G. C. Greubel, Apr 16 2020

A164594 a(n) = ((5 + sqrt(18))*(4 + sqrt(8))^n + (5 - sqrt(18))*(4 - sqrt(8))^n)/2.

Original entry on oeis.org

5, 32, 216, 1472, 10048, 68608, 468480, 3198976, 21843968, 149159936, 1018527744, 6954942464, 47491317760, 324291002368, 2214397476864, 15120851795968, 103251634552832, 705046262054912, 4814357020016640, 32874486063693824, 224481032349417472
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 17 2009

Keywords

Comments

Binomial transform of A101386. Fourth binomial transform of A164737. Inverse binomial transform of A164595.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((5+3*r)*(4+2*r)^n+(5-3*r)*(4-2*r)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 24 2009
    
  • Maple
    A164594:= (n) -> simplify( (2*sqrt(2))^n*(5*ChebyshevU(n, sqrt(2)) - 2*sqrt(2)*ChebyshevU(n-1, sqrt(2))) ); seq( A164594(n), n = 0..25); # G. C. Greubel, Apr 21 2020
  • Mathematica
    CoefficientList[Series[(5-8*x)/(1-8*x+8*x^2), {x,0,25}], x] (* G. C. Greubel, Aug 12 2017 *)
    Table[(2*Sqrt[2])^n*(3*ChebyshevU[n, Sqrt[2]] + 2*ChebyshevT[n, Sqrt[2]]), {n, 0, 25}] (* G. C. Greubel, Apr 21 2020 *)
    LinearRecurrence[{8,-8},{5,32},30] (* Harvey P. Dale, Jul 09 2022 *)
  • PARI
    my(x='x+O('x^25)); Vec((5-8*x)/(1-8*x+8*x^2)) \\ G. C. Greubel, Aug 12 2017
    
  • Sage
    [(2*sqrt(2))^n*(5*chebyshev_U(n, sqrt(2)) - 2*sqrt(2)*chebyshev_U(n-1, sqrt(2))) for n in (0..25)] # G. C. Greubel, Apr 21 2020

Formula

a(n) = 8*a(n-1) - 8*a(n-2) for n > 1; a(0) = 5, a(1) = 32.
G.f.: (5-8*x)/(1-8*x+8*x^2).
E.g.f.: exp(4*x)*(5*cosh(2*sqrt(2)*x) + 3*sqrt(2)*sinh(2*sqrt(2)*x)). - G. C. Greubel, Aug 12 2017
a(n) = (2*sqrt(2))^n * (3*ChebyshevU(n, sqrt(2)) + 2*ChebyshevT(n, sqrt(2))). - G. C. Greubel, Apr 21 2020

Extensions

Extended by Klaus Brockhaus and R. J. Mathar Aug 24 2009

A164595 a(n) = 10*a(n-1) - 17*a(n-2) for n > 1; a(0) = 5, a(1) = 37.

Original entry on oeis.org

5, 37, 285, 2221, 17365, 135893, 1063725, 8327069, 65187365, 510313477, 3994949565, 31274166541, 244827522805, 1916614396853, 15004076080845, 117458316061949, 919513867245125, 7198347299398117, 56351737250814045, 441145468418372461, 3453475150919885845
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 17 2009

Keywords

Comments

Binomial transform of A164594. Fifth binomial transform of A164737.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((5+3*r)*(5+2*r)^n+(5-3*r)*(5-2*r)^n)/2: n in [0..18] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 24 2009
    
  • Maple
    seq(coeff(series( (5-13*x)/(1-10*x+17*x^2) , x, n+1), x, n), n = 0..25); # G. C. Greubel, Apr 21 2020
  • Mathematica
    CoefficientList[Series[(5 -13z)/(1 -10z +17z^2), {z,0,25}], z] (* Vladimir Joseph Stephan Orlovsky, Jun 12 2011 *)
    LinearRecurrence[{10,-17}, {5,37}, 25] (* G. C. Greubel, Aug 11 2017 *)
  • PARI
    my(x='x+O('x^25)); Vec((5-13*x)/(1-10*x+17*x^2)) \\ G. C. Greubel, Aug 11 2017
    
  • Sage
    def A164595_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (5-13*x)/(1-10*x+17*x^2) ).list()
    A164595_list(25) # G. C. Greubel, Apr 21 2020

Formula

a(n) = ((5 + sqrt(18))*(5 + sqrt(8))^n + (5 - sqrt(18))*(5 - sqrt(8))^n)/2.
G.f.: (5-13*x)/(1-10*x+17*x^2).
E.g.f.: exp(5*x)*(5*cosh(2*sqrt(2)*x) + 3*sqrt(2)*sinh(2*sqrt(2)*x)). - G. C. Greubel, Aug 11 2017
a(n) = (1/2)*Sum_{k=0..n} binomial(n,k)*2^(n-k)*(3*Q(2*k+1) + 2*Q(2*k)), where Q(n) are the Pell-Lucas numbers (A002203). - G. C. Greubel, Apr 21 2020

Extensions

Extended by Klaus Brockhaus and R. J. Mathar, Aug 24 2009
Showing 1-4 of 4 results.