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A153081
Nonnegative numbers k such that 2k + 13 is prime.
22
0, 2, 3, 5, 8, 9, 12, 14, 15, 17, 20, 23, 24, 27, 29, 30, 33, 35, 38, 42, 44, 45, 47, 48, 50, 57, 59, 62, 63, 68, 69, 72, 75, 77, 80, 83, 84, 89, 90, 92, 93, 99, 105, 107, 108, 110, 113, 114, 119, 122, 125, 128, 129, 132, 134, 135, 140, 147, 149, 150, 152, 159, 162, 167
OFFSET
1,2
COMMENTS
Or, (p-13)/2 for primes p >= 13.
a(n) = (A000040(n+5) - 13)/2.
a(n) = A005097(n+4) - 6.
a(n) = A067076(n+4) - 5.
a(n) = A089038(n+3) - 4.
a(n) = A105760(n+2) - 3.
a(n) = A101448(n+1) - 1.
a(n) = A089559(n-1) + 1 for n > 1.
LINKS
EXAMPLE
For k = 7, 2*k+13 = 27 is not prime, so 7 is not in the sequence;
for k = 8, 2*k+13 = 29 is prime, so 8 is in the sequence.
MATHEMATICA
(Prime[Range[6, 100]]-13)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)
Select[Range[0, 200], PrimeQ[2#+13]&] (* Harvey P. Dale, Mar 02 2015 *)
PROG
(Magma) [ n: n in [0..200] | IsPrime(2*n+13) ];
(PARI) is(n)=isprime(2*n+13) \\ Charles R Greathouse IV, Jul 12 2016
(Sage) [n for n in (0..200) if is_prime(2*n+13) ] # G. C. Greubel, May 22 2019
(GAP) Filtered([0..200], k-> IsPrime(2*k+13) ) # G. C. Greubel, May 22 2019
CROSSREFS
Cf. A000040 (prime numbers).
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), this seq (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), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).
Sequence in context: A013634 A133484 A181155 * A190841 A095952 A286492
KEYWORD
easy,nonn
AUTHOR
Vincenzo Librandi, Dec 18 2008
EXTENSIONS
Edited and extended by Klaus Brockhaus, Dec 22 2008
Definition clarified by Zak Seidov, Jul 11 2014
STATUS
approved