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 1-3 of 3 results.

A016178 Expansion of g.f. 1/((1 - 7x)*(1 - 9x)).

Original entry on oeis.org

1, 16, 193, 2080, 21121, 206896, 1979713, 18640960, 173533441, 1602154576, 14701866433, 134294124640, 1222488408961, 11099284691056, 100571785292353, 909893629141120, 8222275592839681, 74233110849544336, 669726411243809473, 6038936596379658400, 54430221633714537601
Offset: 0

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Programs

Formula

a(n) = (9^(n+1) - 7^(n+1))/2 = A081202(n+1). Binomial transform of A081034. - R. J. Mathar, Sep 18 2008
From Vincenzo Librandi, Feb 09 2011: (Start)
a(n) = 9*a(n-1) + 7^n, with a(0)=1.
a(n) = 16*a(n-1) - 63*a(n-2), n >= 2. (End)
E.g.f.: exp(7*x)*(9*exp(2*x) - 7)/2. - Stefano Spezia, Jul 23 2024

Extensions

a(18)-a(20) from Stefano Spezia, Jul 23 2024

A081035 8th binomial transform of the periodic sequence (1,9,1,1,9,1...).

Original entry on oeis.org

1, 17, 209, 2273, 23201, 228017, 2186609, 20620673, 192174401, 1775688017, 16304021009, 148995991073, 1356782533601, 12321773100017, 111671069983409, 1010465414433473, 9132169221980801, 82455386442384017, 743959522093353809, 6708663007623467873, 60469158230094196001
Offset: 0

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Author

Paul Barry, Mar 03 2003

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Programs

Formula

a(n) = 9*a(n-1) + 8*7^(n-1).
a(n) = 5*9^n - 4*7^n.
G.f.: (1+x)/((1-7*x)*(1-9*x)). - Vincenzo Librandi, Aug 06 2013
a(0)=1, a(1)=17, a(n)=16*a(n-1)-63*a(n-2). - Harvey P. Dale, Oct 07 2014
E.g.f.: exp(7*x)*(5*exp(2*x) - 4). - Stefano Spezia, Jul 23 2024

A081036 9th binomial transform of the periodic sequence (1,10,1,1,10,1...).

Original entry on oeis.org

1, 19, 262, 3196, 36568, 402544, 4320352, 45562816, 474502528, 4896020224, 50168161792, 511345294336, 5190762354688, 52526098837504, 530208790700032, 5341670325600256, 53733362604802048, 539866900838416384, 5418935206707331072, 54351481653658648576, 544811853229269188608
Offset: 0

Views

Author

Paul Barry, Mar 03 2003

Keywords

Crossrefs

Programs

  • Magma
    [(11/2)*10^n-(9/2)*8^n: n in [0..25]]; // Vincenzo Librandi, Aug 06 2013
  • Mathematica
    CoefficientList[Series[(1 + x)/((1 - 8 x) (1 - 10 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2013 *)
    LinearRecurrence[{18,-80},{1,19},20] (* Harvey P. Dale, Aug 16 2014 *)

Formula

a(n) = 10*a(n-1) + 9*8^(n-1).
a(n) = (11/2)*10^n - (9/2)*8^n.
G.f.: (1+x)/((1-8*x)*(1-10*x)). - Vincenzo Librandi, Aug 06 2013
a(0)=1, a(1)=19, a(n)=18*a(n-1)-80*a(n-2). - Harvey P. Dale, Aug 16 2014
E.g.f.: exp(8*x)*(11*exp(2*x) - 9)/2. - Stefano Spezia, Jul 23 2024

Extensions

Corrected by T. D. Noe, Nov 07 2006
Showing 1-3 of 3 results.