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.

A084351 Length of period of sequences r(k,n)=floor(sin(1)*k!)-n*floor(sin(1)*k!/n) when n is fixed.

Original entry on oeis.org

1, 4, 12, 4, 20, 12, 28, 8, 36, 20, 44, 12, 52, 28, 60, 16, 68, 36, 76, 20, 84, 44, 92, 24, 100, 52, 108, 28, 116, 60, 124, 32, 132, 68, 140, 36, 148, 76, 156, 40, 164, 84, 172, 44, 180, 92, 188, 48, 196, 100, 204, 52, 212, 108, 220, 56, 228, 116, 236, 60, 244, 124, 252
Offset: 1

Views

Author

Benoit Cloitre, Jun 22 2003

Keywords

Crossrefs

Cf. A084348.

Programs

  • PARI
    a(n)=if(n<2,1,if(n%2-1,if(n%4,2*n,n),4*n))

Formula

For n>1 a(n)=n if n==0 (mod 4), a(n)=2n is n==0 (mod 2) and n is not divisible by 4, a(n)=4n if n is odd.
Empirical g.f.: x * (-3*x^8 +4*x^6 +4*x^5 +18*x^4 +4*x^3 +12*x^2 +4*x+1) / (x^8 -2*x^4 +1). - Colin Barker, Jun 16 2013