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A097338 Positive integers n such that 2n-11 is prime. 21
7, 8, 9, 11, 12, 14, 15, 17, 20, 21, 24, 26, 27, 29, 32, 35, 36, 39, 41, 42, 45, 47, 50, 54, 56, 57, 59, 60, 62, 69, 71, 74, 75, 80, 81, 84, 87, 89, 92, 95, 96, 101, 102, 104, 105, 111, 117, 119, 120, 122, 125, 126, 131, 134, 137, 140, 141, 144, 146, 147, 152, 159, 161 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Solutions of the equation (2*n-11)'=1, where n' is the arithmetic derivative of n. - Paolo P. Lava, Nov 15 2012

LINKS

Shawn A. Broyles, Table of n, a(n) for n = 1..1000

FORMULA

Half of p+11 where p is a prime greater than 2.

MATHEMATICA

(Prime[Range[2, 100]]+11)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)

Select[Range[6, 200], PrimeQ[2#-11]&] (* Harvey P. Dale, May 24 2014 *)

PROG

(PARI) is(n)=isprime(2*n-11) \\ Charles R Greathouse IV, Jul 12 2016

CROSSREFS

Cf. A000040.

Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), A101448 (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).

Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), A089253 (k=5), A089192 (k=7), A097069 (k=9), this sequence (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Sequence in context: A035705 A205698 A210147 * A196040 A196043 A030569

Adjacent sequences:  A097335 A097336 A097337 * A097339 A097340 A097341

KEYWORD

easy,nonn

AUTHOR

Douglas Winston (douglas.winston(AT)srupc.com), Sep 17 2004

STATUS

approved

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Last modified October 15 15:03 EDT 2019. Contains 328030 sequences. (Running on oeis4.)