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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A147721 a(n) = C(2,n) DELTA C(0,n).

Original entry on oeis.org

1, 1, 1, 3, 4, 1, 11, 17, 7, 1, 41, 72, 40, 10, 1, 153, 301, 208, 72, 13, 1, 571, 1244, 1021, 446, 113, 16, 1, 2131, 5093, 4819, 2525, 813, 163, 19, 1, 7953, 20688, 22104, 13452, 5218, 1336, 222, 22, 1, 29681, 83481, 99192, 68568, 30986, 9586, 2042, 290, 25, 1
Offset: 0

Views

Author

Paul Barry, Nov 11 2008

Keywords

Comments

Triangle T equal to [1,2,1,0,0,0,...] DELTA [1,0,0,0,...] for Deléham DELTA as in A084938.
T = A147720*A007318. Row sums are A147722.

Examples

			Triangle begins
    1;
    1,   1;
    3,   4,   1;
   11,  17,   7,   1;
   41,  72,  40,  10,   1;
  153, 301, 208,  72,  13,   1;
		

Crossrefs

Programs

  • Mathematica
    nmax=9; Flatten[CoefficientList[Series[CoefficientList[Series[(1 - 3*x)/(1 - 4*x + (1 + y)*x^2 - y*x), {x, 0, nmax}], x], {y, 0, nmax}], y]] (* Indranil Ghosh, Mar 10 2017, after Philippe Deléham *)

Formula

Riordan array ((1-3x)/(1-4x+x^2), x(1-x)/(1-4x+x^2)).
T(n,k) = 4*T(n-1,k) + T(n-1,k-1) - T(n-2,k) - T(n-2,k-1), n > 1. - Philippe Deléham, Feb 13 2012
G.f.: (1-3*x)/(1-4*x+(1+y)*x^2-y*x). - Philippe Deléham, Feb 13 2012
Sum_{k=0..n} T(n,k)*x^k = A000007(n), A001835(n), A147722(n), A084120(n) for x = -1, 0, 1, 2 respectively. - Philippe Deléham, Feb 13 2012

A147841 a(n) = 11*a(n-1) - 9*a(n-2) with a(0)=1, a(1)=9.

Original entry on oeis.org

1, 9, 90, 909, 9189, 92898, 939177, 9494865, 95990922, 970446357, 9810991629, 99186890706, 1002756873105, 10137643587801, 102489267607866, 1036143151396317, 10475171256888693, 105901595463208770, 1070641008783298233, 10823936737447401633, 109427535032871733866, 1106287454724562457829, 11184314186674341431325
Offset: 0

Views

Author

Philippe Deléham, Nov 14 2008

Keywords

Crossrefs

Cf. A147703, A190872, A333344, A333345 (growth power).

Programs

  • Maple
    A147841:= n-> simplify( 3^n*(ChebyshevU(n, 11/6) - (2/3)*ChebyshevU(n-1, 11/6)) ):
    seq(A147841(n), n=0..25); # G. C. Greubel, May 28 2020
  • Mathematica
    Table[3^n*(ChebyshevU[n, 11/6] - (2/3)*ChebyshevU[n-1, 11/6]), {n,0,25}] (* G. C. Greubel, May 28 2020 *)
    LinearRecurrence[{11,-9},{1,9},30] (* Harvey P. Dale, Feb 28 2023 *)
  • PARI
    a(n) = polcoeff(lift(('x-2)*Mod('x,'x^2-11*'x+9)^n), 1); \\ Kevin Ryde, Apr 11 2020

Formula

a(n) = Sum_{k=0..n} A147703(n,k)*8^k.
G.f.: (1-2*x)/(1 -11*x +9*x^2).
a(n) = 9*A333344(n-1) = A190872(n+1) - 2*A190872(n) = A333344(n) - A190872(n). - Kevin Ryde, Apr 11 2020
a(n) = 3^n*(ChebyshevU(n, 11/6) - (2/3)*ChebyshevU(n-1, 11/6)). - G. C. Greubel, May 28 2020
E.g.f.: exp(11*x/2)*(85*cosh(sqrt(85)*x/2) + 7*sqrt(85)*sinh(sqrt(85)*x/2))/85. - Stefano Spezia, Mar 02 2023

Extensions

Entries corrected by Paolo P. Lava, Nov 18 2008
Terms a(18) onward added by G. C. Greubel, May 28 2020

A152174 a(n) = -2*a(n-1)+4*a(n-2), n>1 ; a(0) = 1, a(1) = -4.

Original entry on oeis.org

1, -4, 12, -40, 128, -416, 1344, -4352, 14080, -45568, 147456, -477184, 1544192, -4997120, 16171008, -52330496, 169345024, -548012032, 1773404160, -5738856448, 18571329536, -60098084864, 194481487872, -629355315200
Offset: 0

Views

Author

Philippe Deléham, Nov 27 2008

Keywords

Comments

Signed version of A087206.

Crossrefs

Programs

Formula

G.f.: (1-2x)/(1+2x-4x^2).
a(n) = Sum_{k=0..n} A147703(n,k)*(-5)^k.
a(n) = (-1)^n * A087206(n).

A152167 a(n)=-a(n-1)+3*a(n-2), n>1 ; a(0)=1, a(1)=-3 .

Original entry on oeis.org

1, -3, 6, -15, 33, -78, 177, -411, 942, -2175, 5001, -11526, 26529, -61107, 140694, -324015, 746097, -1718142, 3956433, -9110859, 20980158, -48312735, 111253209, -256191414, 589951041, -1358525283, 3128378406, -7203954255, 16589089473
Offset: 0

Views

Author

Philippe Deléham, Nov 27 2008

Keywords

Crossrefs

Programs

Formula

G.f.: (1-2*x)/(1+x-3*x^2).
a(n) = (-1)^n*A105476(n+1).
a(n) = Sum{k=0..n} A147703(n,k)*(-4)^k.

Extensions

a(19) corrected by Charles R Greathouse IV, Jan 11 2012

A152185 a(n) = -3*a(n-1) + 5*a(n-2), n > 1; a(0)=1, a(1)=-5.

Original entry on oeis.org

1, -5, 20, -85, 355, -1490, 6245, -26185, 109780, -460265, 1929695, -8090410, 33919705, -142211165, 596232020, -2499751885, 10480415755, -43940006690, 184222098845, -772366329985, 3238209484180, -13576460102465
Offset: 0

Views

Author

Philippe Deléham, Nov 28 2008

Keywords

Crossrefs

Programs

Formula

G.f.: (1-2x)/(1+3x-5x^2).
a(n) = Sum_{k=0..n} A147703(n,k)*(-6)^k.
a(n) = (-1)^n*A152187(n). - Philippe Deléham, Nov 29 2008

A152223 a(n) = -4*a(n-1) + 6*a(n-2) for n > 1 with a(0) = 1 and a(1) = -6.

Original entry on oeis.org

1, -6, 30, -156, 804, -4152, 21432, -110640, 571152, -2948448, 15220704, -78573504, 405618240, -2093913984, 10809365376, -55800945408, 288059973888, -1487045568000, 7676542115328, -39628441869312, 204573020169216, -1056062731892736, 5451689048586240
Offset: 0

Views

Author

Philippe Deléham, Nov 29 2008

Keywords

Crossrefs

Cf. A147703.

Programs

  • Haskell
    a152223 n = a152223_list !! n
    a152223_list = 1 : -6 : zipWith (-)
       (map (* 6) $ a152223_list) (map (* 4) $ tail a152223_list)
    -- Reinhard Zumkeller, Jan 12 2012
  • Mathematica
    LinearRecurrence[{-4, 6}, {1, -6}, 23] (* Bruno Berselli, Jan 12 2012 *)
  • PARI
    Vec((1-2*x)/(1+4*x-6*x^2)+O(x^99)) \\ Charles R Greathouse IV, Jan 12 2012
    

Formula

G.f.: (1 - 2*x)/(1 + 4*x - 6*x^2).
a(n) = Sum_{k=0..n} A147703(n,k)*(-7)^k.
a(n) = (1/2)*((-2 - sqrt(10))^n + (-2 + sqrt(10))^n) + (1/5)*sqrt(10)*((-2 - sqrt(10))^n - (-2 + sqrt(10))^n). - Bruno Berselli, Jan 12 2012

Extensions

a(17)-a(23) corrected by Charles R Greathouse IV, Jan 12 2012

A152239 a(n) = -5*a(n-1) + 7*a(n-2) for n > 1 with a(0) = 1 and a(1) = -7.

Original entry on oeis.org

1, -7, 42, -259, 1589, -9758, 59913, -367871, 2258746, -13868827, 85155357, -522858574, 3210380369, -19711911863, 121032221898, -743144492531, 4562948015941, -28016751527422, 172024393748697, -1056239229435439
Offset: 0

Views

Author

Philippe Deléham, Nov 30 2008

Keywords

Crossrefs

Cf. A147703.

Programs

Formula

G.f.: (1 - 2*x)/(1 + 5*x - 7*x^2).
a(n) = Sum_{k=0..n} A147703(n,k)*(-8)^k.

Extensions

Several terms corrected by Johannes W. Meijer, Aug 17 2010

A147838 a(n)=8*a(n-1)-6*a(n-2), a(0)=1, a(1)=6 .

Original entry on oeis.org

1, 6, 42, 300, 2148, 15384, 110184, 789168, 5652240, 40482912, 289949856, 2076701376, 14873911872, 106531086720, 763005222528, 5464855259904, 39140810744064, 280337354393088, 2007853970680320, 14380807639084032
Offset: 0

Views

Author

Philippe Deléham, Nov 14 2008

Keywords

Programs

  • Mathematica
    LinearRecurrence[{8,-6},{1,6},40] (* Harvey P. Dale, Mar 01 2012 *)

Formula

a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*5^k . G.f.: (1-2x)/(1-8x+6*x^2).
a(n)= ((5+sqrt(10))/10)*(4+sqrt(10))^n + ((5-sqrt(10))/10)*(4-sqrt(10))^n [From Richard Choulet, Nov 20 2008]

A152594 a(n) = -5*a(n-1)-2*a(n-2), n>1 ; a(0)=1, a(1)=-1 .

Original entry on oeis.org

1, -1, 3, -13, 59, -269, 1227, -5597, 25531, -116461, 531243, -2423293, 11053979, -50423309, 230008587, -1049196317, 4785964411, -21831429421, 99585218283, -454263232573, 2072145726299, -9452202166349, 43116719379147
Offset: 0

Views

Author

Philippe Deléham, Dec 09 2008

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{-5,-2},{1,-1},30] (* Harvey P. Dale, Jun 18 2015 *)

Formula

G.f.: (1+4*x)/(1+5*x+2*x^2).
a(n) = Sum_{k=0..n-1} A147703(n,k)*(-2)^(n-k).
a(n) = (-1)^n*A052984(n-1), n>=1 ; a(0)=1.
E.g.f.: exp(-5*x/2)*(17*cosh(sqrt(17)*x/2) + 3*sqrt(17)*sinh(sqrt(17)*x/2))/17. - Stefano Spezia, Jun 17 2025

A152596 a(n) = 7*a(n-1) - 6*a(n-2), n>1; a(0)=1, a(1)=3.

Original entry on oeis.org

1, 3, 15, 87, 519, 3111, 18663, 111975, 671847, 4031079, 24186471, 145118823, 870712935, 5224277607, 31345665639, 188073993831, 1128443962983, 6770663777895, 40623982667367, 243743896004199, 1462463376025191, 8774780256151143, 52648681536906855, 315892089221441127
Offset: 0

Views

Author

Philippe Deléham, Dec 09 2008

Keywords

Crossrefs

Cf. A147703.

Programs

Formula

G.f.: (1-4*x)/(1 - 7*x + 6*x^2).
a(n) = Sum_{k=0..n} A147703(n,k)*2^(n-k).
a(n) = (1/5)*(3 + 2*6^n), with n>=0. - Paolo P. Lava, Dec 12 2008
E.g.f.: exp(x)*(3 + 2*exp(5*x))/5. - Stefano Spezia, Sep 30 2023

Extensions

a(21)-a(23) from Stefano Spezia, Sep 30 2023
Previous Showing 11-20 of 27 results. Next