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 1-5 of 5 results.

A048772 Partial sums of A048696.

Original entry on oeis.org

1, 10, 29, 76, 189, 462, 1121, 2712, 6553, 15826, 38213, 92260, 222741, 537750, 1298249, 3134256, 7566769, 18267802, 44102381, 106472572, 257047533, 620567646, 1498182833
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Haskell
    a048772 n = a048772_list !! n
    a048772_list = scanl1 (+) a048696_list
    -- Reinhard Zumkeller, Dec 15 2013
    
  • Mathematica
    Accumulate[LinearRecurrence[{2,1},{1,9},30]] (* or *) LinearRecurrence[ {3,-1,-1},{1,10,29},30] (* Harvey P. Dale, Apr 20 2012 *)
  • PARI
    a(n)=([0,1,0; 0,0,1; -1,-1,3]^n*[1;10;29])[1,1] \\ Charles R Greathouse IV, Feb 10 2017

Formula

a(n)=2*a(n-1)+a(n-2)+8; a(0)=1, a(1)=10.
a(n)=[ {(9+5*sqrt(2))(1+sqrt(2))^n - (9-5*sqrt(2))(1-sqrt(2))^n}/2*sqrt(2) ]-4.
a(0)=1, a(1)=10, a(2)=29, a(n)=3*a(n-1)-a(n-2)-a(n-3). - Harvey P. Dale, Apr 20 2012
G.f. ( 1+7*x ) / ( (x-1)*(x^2+2*x-1) ). a(n)=A048739(n)+7*A048739(n-1). - R. J. Mathar, Nov 08 2012

A164298 a(n) = ((1+4*sqrt(2))*(2+sqrt(2))^n + (1-4*sqrt(2))*(2-sqrt(2))^n)/2.

Original entry on oeis.org

1, 10, 38, 132, 452, 1544, 5272, 18000, 61456, 209824, 716384, 2445888, 8350784, 28511360, 97343872, 332352768, 1134723328, 3874187776, 13227304448, 45160842240, 154188760064, 526433355776, 1797355902976, 6136556900352, 20951515795456, 71532949381120
Offset: 0

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Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 12 2009

Keywords

Comments

Binomial transform of A048696. Second binomial transform of A164587. Inverse binomial transform of A164299.
This sequence is part of a class of sequences defined by the recurrence a(n,m) = 2*(m+1)*a(n-1,m) - ((m+1)^2 - 2)*a(n-2,m) with a(0) = 1 and a(1) = m+9. The generating function is Sum_{n>=0} a(n,m)*x^n = (1 - (m-7)*x)/(1 - 2*(m+1)*x + ((m+1)^2 - 2)*x^2) and has a series expansion in terms of Pell-Lucas numbers defined by a(n, m) = (1/2)*Sum_{k=0..n} binomial(n,k)*m^(n-k)*(5*Q(k) + 4*Q(k-1)). - G. C. Greubel, Mar 12 2021

Crossrefs

Sequences in the class a(n, m): this sequence (m=1), A164299 (m=2), A164300 (m=3), A164301 (m=4), A164598 (m=5), A164599 (m=6), A081185 (m=7), A164600 (m=8).
Cf. A016116(n+1).

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((1+4*r)*(2+r)^n+(1-4*r)*(2-r)^n)/2: n in [0..27] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 17 2009
    
  • Magma
    m:=50; R:=PowerSeriesRing(Integers(), m); Coefficients(R!( (1+6*x)/(1-4*x+2*x^2) )); // G. C. Greubel, Dec 14 2018
    
  • Maple
    a:=n->((1+4*sqrt(2))*(2+sqrt(2))^n+(1-4*sqrt(2))*(2-sqrt(2))^n)/2: seq(floor(a(n)),n=0..25); # Muniru A Asiru, Dec 15 2018
  • Mathematica
    LinearRecurrence[{4,-2}, {1,10}, 50] (* or *) CoefficientList[Series[(1 + 6*x)/(1 - 4*x + 2*x^2), {x,0,50}], x] (* G. C. Greubel, Sep 12 2017 *)
  • PARI
    my(x='x+O('x^50)); Vec((1+6*x)/(1-4*x+2*x^2)) \\ G. C. Greubel, Sep 12 2017
    
  • Sage
    [( (1+6*x)/(1-4*x+2*x^2) ).series(x,n+1).list()[n] for n in (0..30)] # G. C. Greubel, Dec 14 2018; Mar 12 2021

Formula

a(n) = 4*a(n-1) - 2*a(n-2) for n > 1; a(0)=1, a(1)=10.
G.f.: (1+6*x)/(1-4*x+2*x^2).
E.g.f.: (cosh(sqrt(2)*x) + 4*sqrt(2)*sinh(sqrt(2)*x))*exp(2*x). - G. C. Greubel, Sep 12 2017
From G. C. Greubel, Mar 12 2021: (Start)
a(n) = A056236(n) + 8*A007070(n-1).
a(n) = (1/2)*Sum_{k=0..n} binomial(n,k)*(5*Q(k) + 4*Q(k-1)), where Q(n) = Pell-Lucas(n) = A002203(n). (End)

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Aug 17 2009

A164587 a(n) = 2*a(n - 2) for n > 2; a(1) = 1, a(2) = 8.

Original entry on oeis.org

1, 8, 2, 16, 4, 32, 8, 64, 16, 128, 32, 256, 64, 512, 128, 1024, 256, 2048, 512, 4096, 1024, 8192, 2048, 16384, 4096, 32768, 8192, 65536, 16384, 131072, 32768, 262144, 65536, 524288, 131072, 1048576, 262144, 2097152, 524288, 4194304, 1048576
Offset: 1

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Author

Klaus Brockhaus, Aug 17 2009

Keywords

Comments

Interleaving of A000079 and A000079 without initial terms 1, 2, 4.
Binomial transform is A048696. Second binomial transform is A164298.

Crossrefs

Equals A112032 without initial term 4.
Cf. A000079 (powers of 2), A048696, A164298.

Programs

  • Magma
    [ n le 2 select 7*n-6 else 2*Self(n-2): n in [1..41] ];
    
  • Mathematica
    CoefficientList[Series[(1 - x)/(1 - 10*x + 17*x^2), {x,0,50}], x] (* G. C. Greubel, Aug 12 2017 *)
  • PARI
    x='x+O('x^50); Vec(x*(1+8*x)/(1-2*x^2)) \\ G. C. Greubel, Aug 12 2017

Formula

a(n) = (5 + 3*(-1)^n)*2^((2*n -5 +(-1)^n)/4).
G.f.: x*(1+8*x)/(1-2*x^2).
E.g.f.: 4*cosh(sqrt(2)*x) + (1/sqrt(2))*sinh(sqrt(2)*x) - 4. - G. C. Greubel, Aug 12 2017

A105082 Expansion of (5+4x)/(1-2x-x^2).

Original entry on oeis.org

5, 14, 33, 80, 193, 466, 1125, 2716, 6557, 15830, 38217, 92264, 222745, 537754, 1298253, 3134260, 7566773, 18267806, 44102385, 106472576, 257047537, 620567650, 1498182837, 3616933324, 8732049485, 21081032294, 50894114073
Offset: 0

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Author

Creighton Dement, Apr 06 2005

Keywords

Comments

A floretion-generated, Pellian related sequence.
Floretion Algebra Multiplication Program, FAMP Code: lesloop(infty)-tesforseq[ + .25'i + .25i' - .25'ii' - .25'jj' - .25'kk' + .25'jk' + .25'kj' - .25e ], Fortype: 1A.
For n > 0: A048696(n) = a(n) - a(n-1). - Reinhard Zumkeller, Dec 15 2013

Crossrefs

Programs

  • Haskell
    a105082 n = a105082_list !! n
    a105082_list = scanl (+) 5 $ tail a048696_list
    -- Reinhard Zumkeller, Dec 15 2013

Formula

a(n+2) = 2*a(n+1) + a(n); FAMP result: a(n) = 2*A001333(n) + 3*A048654(n); SuperSeeker results: a(n+1) - a(n) = A048696(n+1); a(n) + a(n+1) = A048696(n+2)
a(n) = ((9+5*sqrt(2))*(1+sqrt(2))^n - (9-5*sqrt(2))*(1-sqrt(2))^n)/(2*sqrt(2)) - Lambert Herrgesell (zero815(AT)googlemail.com), Jan 26 2007

A048773 Partial sums of A048697.

Original entry on oeis.org

1, 11, 32, 84, 209, 511, 1240, 3000, 7249, 17507, 42272, 102060, 246401, 594871, 1436152, 3467184, 8370529, 20208251, 48787040, 117782340, 284351729, 686485807, 1657323352, 4001132520, 9659588401, 23320309331, 56300207072, 135920723484, 328141654049
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Accumulate[LinearRecurrence[{2,1},{1,10},35]] (* Harvey P. Dale, Jul 26 2011 *)
    LinearRecurrence[{3, -1, -1},{1, 11, 32},29] (* Ray Chandler, Aug 03 2015 *)

Formula

a(n) = 2*a(n-1)+a(n-2)+9; a(0)=1, a(1)=11.
a(n) = (((10+(11/2)*sqrt(2))*(1+sqrt(2))^n - (10-(11/2)*sqrt(2))*(1-sqrt(2))^n)/ 2*sqrt(2))-9/2.
From R. J. Mathar, Nov 08 2012: (Start)
G.f.: ( 1+8*x ) / ( (x-1)*(x^2+2*x-1) ).
a(n) = A048739(n)+8*A048739(n-1). (End)
a(n) = 3*a(n-1)-a(n-2)-a(n-3). - Wesley Ivan Hurt, May 21 2021

Extensions

More terms from Harvey P. Dale, Jul 26 2011
Showing 1-5 of 5 results.