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.

A062300 a(n) = floor(cosec(Pi/(n+1))).

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25
Offset: 1

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Author

Amarnath Murthy, Jun 19 2001

Keywords

Comments

cosec = 1/sin. - Kevin Ryde observes that this sequences is up to the offset almost identical to A032615(n) = floor(n/Pi): the values differ after n=6 for the first time again at n=80143857. Robert Israel shows that we can nonetheless expect infinitely many differences. See the posts on the SeqFan list for details. - M. F. Hasler, Oct 19 2016

Examples

			a(99) = 31 as cosec{Pi/100} =31.8362252090976229556628738787913...
		

Crossrefs

Cf. A032615.

Programs

  • PARI
    v=vector(150,n,floor(1/sin(Pi/(n+1)))) \\ Warning: for n=5 this may yield an incorrect value of 1 instead of a(n)=2, depending on default(realprecision).
    
  • PARI
    { default(realprecision, 50); for (n=1, 1000, write("b062300.txt", n, " ", floor(1/sin(Pi/(n+1)))) ) } \\ Harry J. Smith, Aug 04 2009
    
  • PARI
    A062300(n,e=.1^precision(.1))=1\sin(Pi/(n+1+e)) \\ M. F. Hasler, Oct 19 2016

Extensions

More terms from Jason Earls, Jun 22 2001