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.

A272127 a(n) = 1680*n^4 - 168*n^2 + 128*n + 1.

Original entry on oeis.org

1, 1641, 26465, 134953, 427905, 1046441, 2172001, 4026345, 6871553, 11010025, 16784481, 24577961, 34813825, 47955753, 64507745, 85014121, 110059521, 140268905, 176307553, 218881065, 268735361, 326656681, 393471585, 470046953, 557289985, 656148201, 767609441
Offset: 0

Views

Author

Vincenzo Librandi, Apr 25 2016

Keywords

Comments

This is the polynomial Qbar(4,n) in Brent. See A160485 for the triangle of coefficients (with signs) of the Qbar polynomials. - Peter Bala, Jan 21 2019

Crossrefs

Programs

  • Magma
    [1680*n^4-168*n^2+128*n+1: n in [0..50]];
    
  • Mathematica
    Table[1680 n^4 - 168 n^2 + 128 n + 1, {n, 0, 30}]
    LinearRecurrence[{5,-10,10,-5,1},{1,1641,26465,134953,427905},30] (* Harvey P. Dale, Nov 27 2017 *)
  • PARI
    a(n) = 1680*n^4 - 168*n^2 + 128*n + 1; \\ Altug Alkan, Apr 30 2016

Formula

O.g.f.: (1+1636*x+18270*x^2+19028*x^3+1385*x^4)/(1-x)^5.
E.g.f.: (1+1640*x+11592*x^2+10080*x^3+1680*x^4)*exp(x).
a(n) = (2*n+1)*(840*n^3-420*n^2+126*n+1).
a(n) = 5*a(n-1)-10*a(n-2)+10*a(n-3)-5*a(n-4)+a(n-5), for n>4
See page 7 in Brent's paper:
a(n) = (2*n+1)^2*A272126(n) - 2*n*(2*n+1)*A272126(n-1).
A272128(n) = (2*n+1)^2*a(n) - 2*n*(2*n+1)*a(n-1).
From Peter Bala, Jan 22 2019: (Start)
a(n) = 1/4^n * Sum_{k = 0..n} (2*k + 1)^8 * binomial(2*n + 1, n - k).
a(n-1) = 2/4^n * binomial(2*n,n) * ( 1 + 3^8*(n - 1)/(n + 1) + 5^8*(n - 1)*(n - 2)/((n + 1)*(n + 2)) + 7^8*(n - 1)*(n - 2)*(n - 3)/((n + 1)*(n + 2)*(n + 3)) + ... ). (End)

A272129 a(n) = 32*n^2 - 56*n + 25.

Original entry on oeis.org

25, 1, 41, 145, 313, 545, 841, 1201, 1625, 2113, 2665, 3281, 3961, 4705, 5513, 6385, 7321, 8321, 9385, 10513, 11705, 12961, 14281, 15665, 17113, 18625, 20201, 21841, 23545, 25313, 27145, 29041, 31001, 33025, 35113, 37265, 39481, 41761, 44105, 46513, 48985
Offset: 0

Views

Author

Vincenzo Librandi, Apr 26 2016

Keywords

Comments

Subsequence of A001844.

Crossrefs

Programs

  • Magma
    [32*n^2 - 56*n + 25: n in [0..50]];
    
  • Maple
    [32*n^2-56*n+25$n=0..40]; # Muniru A Asiru, Jan 28 2019
  • Mathematica
    Table[32 n^2 - 56 n + 25, {n, 0, 40}]
    LinearRecurrence[{3,-3,1},{25,1,41},50] (* Harvey P. Dale, Jul 03 2018 *)
  • PARI
    lista(nn) = for(n=0, nn, print1(32*n^2-56*n+25, ", ")); \\ Altug Alkan, Apr 26 2016

Formula

O.g.f.: (25 - 74*x + 113*x^2)/(1-x)^3.
E.g.f.: (25 - 24*x + 32*x^2)*exp(x).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
n*a(n) = 1 + 3^5*(n-1)/(n+1) + 5^5*((n-1)*(n-2))/((n+1)*(n+2)) + ... for n >= 1. See A245244. - Peter Bala, Jan 19 2019

A272128 a(n) = 30240*n^5-25200*n^4+5040*n^3+7320*n^2-2638*n+1.

Original entry on oeis.org

1, 14763, 628805, 5501167, 24943689, 79549811, 203823373, 449807415, 890712977, 1624547899, 2777745621, 4508793983, 7011864025, 10520438787, 15310942109, 21706367431, 30079906593, 40858578635, 54526858597, 71630306319, 92779195241, 118652141203
Offset: 0

Views

Author

Vincenzo Librandi, Apr 25 2016

Keywords

Comments

This is the polynomial Qbar(5,n) in Brent. See A160485 for the triangle of coefficients (with signs) of the Qbar polynomials. - Peter Bala, Feb 01 2019

Crossrefs

Programs

  • Magma
    [30240*n^5-25200*n^4+5040*n^3+7320*n^2-2638*n+1: n in [0..40]];
    
  • Mathematica
    Table[30240 n^5 - 25200 n^4 + 5040 n^3 + 7320 n^2 - 2638 n + 1, {n, 0, 30}]
  • PARI
    a(n)=30240*n^5-25200*n^4+5040*n^3+7320*n^2-2638*n+1 \\ Charles R Greathouse IV, Apr 30 2016

Formula

O.g.f.: (1 + 14757*x + 540242*x^2 + 1949762*x^3 + 1073517*x^4 + 50521*x^5)/(1-x)^6.
E.g.f.: (1 + 14762*x + 299640*x^2 + 609840*x^3 + 277200*x^4 + 30240*x^5)*exp(x).
a(n) = (2*n+1)*(15120*n^4-20160*n^3+12600*n^2-2640*n+1).
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6).
See page 7 in Brent's paper: a(n) = (2*n+1)^2*A272127(n) - 2*n*(2*n+1)*A272127(n-1).
From Peter Bala, Feb 01 2019: (Start)
a(n) = 1/4^n * Sum_{k = 0..n} (2*k + 1)^10 * binomial(2*n + 1, n - k).
a(n-1) = 2/4^n * binomial(2*n,n) * ( 1 + 3^10*(n - 1)/(n + 1) + 5^10*(n - 1)*(n - 2)/((n + 1)*(n + 2)) + 7^10*(n - 1)*(n - 2)*(n - 3)/((n + 1)*(n + 2)*(n + 3)) + ... ). (End)
Showing 1-3 of 3 results.