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a(n) = floor(cosec(Pi/(n+1))).
3

%I #25 Jan 02 2023 12:30:46

%S 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,

%T 11,11,11,12,12,12,13,13,13,14,14,14,14,15,15,15,16,16,16,17,17,17,18,

%U 18,18,19,19,19,20,20,20,21,21,21,21,22,22,22,23,23,23,24,24,24,25,25

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

%C 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

%H Harry J. Smith, <a href="/A062300/b062300.txt">Table of n, a(n) for n=1..1000</a>

%H R. Israel, in reply to K. Ryde, <a href="http://list.seqfan.eu/oldermail/seqfan/2016-October/016857.html">Re: nearly equal floor(n/Pi) A032615 and A062300</a>, SeqFan list, Oct 19 2016

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

%o (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).

%o (PARI) { default(realprecision, 50); for (n=1, 1000, write("b062300.txt", n, " ", floor(1/sin(Pi/(n+1)))) ) } \\ _Harry J. Smith_, Aug 04 2009

%o (PARI) A062300(n,e=.1^precision(.1))=1\sin(Pi/(n+1+e)) \\ _M. F. Hasler_, Oct 19 2016

%Y Cf. A032615.

%K nonn,easy

%O 1,5

%A _Amarnath Murthy_, Jun 19 2001

%E More terms from _Jason Earls_, Jun 22 2001