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.

A054340 10-fold convolution of A000302 (powers of 4).

Original entry on oeis.org

1, 40, 880, 14080, 183040, 2050048, 20500480, 187432960, 1593180160, 12745441280, 96865353728, 704475299840, 4931327098880, 33381291130880, 219362770288640, 1403921729847296, 8774510811545600, 53679360258867200, 322076161553203200, 1898554215471513600
Offset: 0

Views

Author

Wolfdieter Lang, Mar 13 2000

Keywords

Comments

With a different offset, number of n-permutations (n>=9) of 5 objects: u, v, z, x, y with repetition allowed, containing exactly nine (9) u's. - Zerinvary Lajos, Jul 02 2008

Crossrefs

Programs

  • GAP
    List([0..20], n-> 4^n*Binomial(n+9, 9)); # G. C. Greubel, Jul 21 2019
  • Magma
    [4^n*Binomial(n+9, 9): n in [0..20]]; // Vincenzo Librandi, Oct 15 2011
    
  • Maple
    seq(binomial(n+9,9)*4^n,n=0..20); # Zerinvary Lajos, Jul 02 2008
  • Mathematica
    Table[4^n*Binomial[n+9,9], {n,0,20}] (* G. C. Greubel, Jul 21 2019 *)
  • PARI
    vector(20, n, n--; 4^n*binomial(n+9, 9)) \\ G. C. Greubel, Jul 21 2019
    

Formula

a(n) = binomial(n+9, 9)*4^n.
G.f.: 1/(1 - 4*x)^10.
a(n) = A054335(n+19, 19).
E.g.f.: (2^7/9!)*(2835 + 102060*x + 816480*x^2 + 2540160*x^3 + 3810240*x^4 + 3048192*x^5 + 1354752*x^6 + 331776*x^7 + 41472*x^8 + 2048*x^9)*exp(4*x).
From Amiram Eldar, Mar 27 2022: (Start)
Sum_{n>=0} 1/a(n) = 236196*log(4/3) - 4756383/70.
Sum_{n>=0} (-1)^n/a(n) = 14062500*log(5/4) - 43931373/14. (End)