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A227957 Number of primes that are of the form n - 2^k - k^2. 0
0, 0, 1, 1, 1, 2, 0, 2, 0, 2, 1, 1, 1, 2, 1, 1, 0, 1, 2, 3, 1, 2, 0, 2, 1, 1, 1, 1, 0, 2, 1, 2, 0, 3, 1, 1, 2, 1, 2, 2, 0, 1, 1, 2, 2, 2, 0, 2, 2, 1, 2, 0, 0, 2, 2, 1, 0, 1, 1, 3, 2, 3, 1, 3, 0, 0, 1, 2, 2, 3, 0, 1, 1, 3, 2, 3, 0, 1, 2, 2, 1, 1, 0, 2, 1, 2, 1, 2, 0, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
COMMENTS
Indices of zeros in the sequence are 1, 2, 7, 9, 17, 23, 29, 33, 41, 47, 52, ...
LINKS
PROG
(PARI) a(n)=sum(k=0, log(n)\log(2), isprime(n-2^k-k^2)) \\ Charles R Greathouse IV, Mar 18 2014
CROSSREFS
Sequence in context: A052511 A054533 A339927 * A305575 A247977 A359239
KEYWORD
nonn,less
AUTHOR
Irina Gerasimova, Oct 26 2013
EXTENSIONS
Terms corrected by R. J. Mathar, Oct 26 2013
STATUS
approved

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Last modified March 29 06:15 EDT 2024. Contains 371265 sequences. (Running on oeis4.)