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A187733 Primes of the form 2^n + n + 2. 2
3, 5, 13, 137, 523, 524309, 134217757, 8589934627, 178405961588244985132285746181186892047843477 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The list of associated n is: 0, 1, 3, 7, 9, 19, 27, 33, 147, 639, ...
Primes from A052968 of the form 2^(n-1) + n + 1 for n = 1, 2, 4, 8, 10, 20, 28, 34, ...
Pairs of twin primes of forms (2^n+n; 2^n+n+2): (3; 5), (11; 13), (521; 523), ...
The prime number a(10) = 2^639 + 639 + 2 has 193 digits.
a(11) = 2^12243 + 12243 + 2 and a(12) = 2^41427 + 41427 + 2. - Giovanni Resta, Jan 23 2013
The sequence contains the subsequence 13, 137, 524309,... where the n themselves are prime, n = 3, 7, 19 (no further up to 41427). - Jaroslav Krizek, Feb 27 2013
LINKS
FactorDB, 2^n + n + 2.
EXAMPLE
8589934627 is in the sequence since 8589934627 = 2^33 + 33 + 2 and 8589934627 is prime.
MATHEMATICA
Select[Table[2^n + n + 2, {n, 60}], PrimeQ[#] &]
CROSSREFS
Sequence in context: A053630 A155012 A121533 * A087170 A123370 A110407
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 19 2013
STATUS
approved

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Last modified March 19 01:22 EDT 2024. Contains 370952 sequences. (Running on oeis4.)