login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A220850 a(n+1) is equal to a(n) plus the number of primes between a(n) and 2*a(n) inclusively. 2
1, 2, 4, 6, 8, 10, 14, 17, 22, 28, 35, 43, 53, 65, 78, 93, 111, 129, 153, 179, 210, 245, 285, 328, 381, 441, 508, 582, 668, 764, 870, 990, 1123, 1270, 1436, 1625, 1825, 2054, 2309, 2590, 2904, 3246, 3631, 4052, 4512, 5022, 5582, 6197, 6872, 7612, 8421, 9312 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..558

EXAMPLE

a(6) = the number of primes between a(5) and 2*a(5) plus a(5) = the number of primes [8, 16] + 8 = 2 + 8 = 10.

MATHEMATICA

f[n_] := PrimePi[ 2n] - PrimePi[n - 1]; NestList[# +f@# &, 1, 50]

CROSSREFS

Cf. A035250, A220851, inspired by A084140.

Sequence in context: A180081 A242418 A191146 * A151566 A160406 A113293

Adjacent sequences:  A220847 A220848 A220849 * A220851 A220852 A220853

KEYWORD

easy,nonn

AUTHOR

Robert G. Wilson v, Dec 22 2012

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 18 02:19 EDT 2020. Contains 337164 sequences. (Running on oeis4.)