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.

A060613 Number of n X n {-1,0,1} matrices with no zero rows.

Original entry on oeis.org

2, 64, 17576, 40960000, 829997587232, 148863517207035904, 238534446168822298080896, 3429499272008000182681600000000, 443223773846454955204927262062339154432
Offset: 1

Views

Author

Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 25 2001

Keywords

Crossrefs

Programs

  • PARI
    a(n)={(3^n - 1)^n} \\ Harry J. Smith, Jul 08 2009
    
  • PARI
    {a(n, q=3, m=1, b=-1)=(m*q^n + b)^n} \\ Paul D. Hanna, Dec 26 2011
    
  • PARI
    /* E.g.f. series identity: */
    {a(n, q=3, m=1, b=-1)=n!*polcoeff(sum(k=0, n, m^k*q^(k^2)*exp(b*q^k*x+x*O(x^n))*x^k/k!), n)} \\ Paul D. Hanna, Dec 26 2011
    
  • PARI
    /* O.g.f. series identity: */
    {a(n, q=3, m=1, b=-1)=polcoeff(sum(k=0, n, m^k*q^(k^2)*x^k/(1-b*q^k*x+x*O(x^n))^(k+1)), n)} \\ Paul D. Hanna, Dec 26 2011

Formula

a(n) = (3^n - 1)^n.
E.g.f.: Sum_{n>=0} 3^(n^2) * exp(-3^n*x) * x^n/n!. - Paul D. Hanna, Dec 26 2011
O.g.f.: Sum_{n>=0} 3^(n^2) * x^n/(1+3^n*x)^(n+1). - Paul D. Hanna, Dec 26 2011

Extensions

More terms from Harry J. Smith, Jul 08 2009