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.

A090013 Permanent of (0,1)-matrix of size n X (n+d) with d=3 and n-1 zeros not on a line.

Original entry on oeis.org

4, 16, 84, 536, 4004, 34176, 327604, 3481096, 40585284, 514872176, 7058605844, 103969203576, 1637182717924, 27442553929696, 487806792137844, 9164718013496936, 181446744138509444, 3775570370986139856
Offset: 1

Views

Author

Jaap Spies, Dec 13 2003

Keywords

References

  • Brualdi, Richard A. and Ryser, Herbert J., Combinatorial Matrix Theory, Cambridge NY (1991), Chapter 7.

Crossrefs

Programs

  • Mathematica
    t={4,16};Do[AppendTo[t,(n+2)*t[[-1]]+(n-2)*t[[-2]]],{n,3,18}];t (* Indranil Ghosh, Feb 21 2017 *)

Formula

a(n) = (n+2)*a(n-1) + (n-2)*a(n-2), a(1)=4, a(2)=16
a(n) ~ exp(-1) * n! * n^3 / 6. - Vaclav Kotesovec, Nov 30 2017

Extensions

Corrected by Jaap Spies, Jan 26 2004