login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A074766 a(n) = prime(2n) - 2*prime(n) - n. 1
-2, -1, 0, 1, 2, 5, 2, 7, 6, 3, 6, 3, 6, 7, 4, 9, 4, 11, 10, 11, 14, 13, 10, 21, 10, 11, 18, 21, 24, 25, 8, 17, 10, 25, 16, 21, 22, 19, 24, 23, 22, 29, 18, 27, 24, 35, 22, 9, 18, 33, 40, 39, 42, 37, 32, 31, 24, 41, 34, 37, 46, 35, 24, 33, 42, 43, 28, 27, 24, 41, 44, 37, 32, 37, 30, 39, 32 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Conjecture: p(2n) - 2p(n) < 2n for all n.

LINKS

Table of n, a(n) for n=1..77.

FORMULA

a(n) = A066066(n) - n.

EXAMPLE

a(9) = p(18) - 2p(9) - 9 = 61 - 2*23 - 9 = 6.

MAPLE

A074766:=n->ithprime(2*n)-2*ithprime(n)-n: seq(A074766(n), n=1..100); # Wesley Ivan Hurt, Jan 16 2017

MATHEMATICA

Table[Prime[2 n] - 2 Prime[n] - n, {n, 80}] (* Harvey P. Dale, Mar 04 2017 *)

CROSSREFS

Cf. A066066.

Sequence in context: A277239 A138352 A129620 * A138107 A089631 A298878

Adjacent sequences:  A074763 A074764 A074765 * A074767 A074768 A074769

KEYWORD

sign

AUTHOR

Werner D. Sand, Sep 29 2002

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 16 04:54 EST 2018. Contains 317255 sequences. (Running on oeis4.)