login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A097427 Integer part of the area of circles with prime radii. 0
12, 28, 78, 153, 380, 530, 907, 1134, 1661, 2642, 3019, 4300, 5281, 5808, 6939, 8824, 10935, 11689, 14102, 15836, 16741, 19606, 21642, 24884, 29559, 32047, 33329, 35968, 37325, 40114, 50670, 53912, 58964, 60698, 69746, 71631, 77437, 83468 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Area = Pi * r^2.

LINKS

Table of n, a(n) for n=1..38.

FORMULA

a(n) = floor(Pi*prime(n)^2). - Michel Marcus, Mar 11 2015

EXAMPLE

a(2) = floor(Pi*prime(2)^2) = floor(Pi*9) = 28.

PROG

(PARI) f(n) = forprime(x=1, n, print1(floor(Pi*x^2)", "))

(MAGMA) [Floor(Pi(RealField(2*n))*NthPrime(n)^2): n in [1..80]]; // Vincenzo Librandi, Mar 11 2015

CROSSREFS

Sequence in context: A248547 A164533 A034319 * A039366 A043189 A043969

Adjacent sequences:  A097424 A097425 A097426 * A097428 A097429 A097430

KEYWORD

nonn

AUTHOR

Cino Hilliard, Aug 22 2004

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 13 05:18 EDT 2022. Contains 356077 sequences. (Running on oeis4.)