A214491 Smallest integer k such that prime(n+1) = floor(prime(n)/cos(k)).

1, 1, 18, 70, 12, 7, 56, 76, 81, 13, 32, 57, 82, 13, 144, 101, 6, 13, 163, 6, 31, 82, 119, 31, 6, 138, 6, 138, 6, 145, 50, 38, 107, 119, 63, 6, 6, 138, 6, 50, 19, 126, 19, 151, 19, 207, 126, 151, 19, 107, 138, 19, 339, 138, 138, 182, 25, 182, 107, 25, 50, 295

Offset

1,3

Comments

a(n) is given in radians.

See the comments in A214490.

Links

Table of n, a(n) for n=1..62.

Example

a(2) = 1 because prime(2+1) = floor(prime(2) / cos(1)) = floor(3/.5403023059...) =  floor(5.552447153…) = 5 = prime(3).

Maple

with(numtheory):for n from 1 to 65 do:i:=0:p0:=ithprime(n):p1:=ithprime(n+1):for k from 0 to 10^7 while(i=0) do:c:=cos(k):if c<>0 and p1=floor(p0/c) then i:=1:printf(`%d, `, k):else fi:od:od:

Crossrefs

Cf. A000040, A214490.

Sequence in context: A045234 A158056 A304061 * A135470 A059224 A174492

Adjacent sequences: A214488 A214489 A214490 * A214492 A214493 A214494

Keyword

nonn

Author

Michel Lagneau, Jul 19 2012

Status

approved