A278287 Number of primes of the form 4k+3 such that 4(n - k) - 3 is 1 or prime where (4k+3)/3 >= n.

1, 1, 1, 0, 1, 2, 1, 1, 1, 0, 1, 2, 1, 1, 2, 1, 1, 3, 2, 2, 4, 2, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 3, 2, 2, 3, 1, 2, 3, 1, 3, 5, 2, 2, 5, 2, 1, 4, 3, 2, 4, 3, 2, 4, 3, 2, 5, 3, 2, 5, 3, 1, 6, 3, 2, 4, 4, 2, 4, 4, 3, 4, 3, 2, 5, 2, 2, 6, 2, 2, 6, 1, 2, 4, 1, 2, 4, 2, 1, 5, 3, 3, 5, 2, 3, 6, 3

Offset

1,6

Comments

Where 4(n - k) - 3 is a positive noncomposite number of the form 4m+1 (A280084).

Links

Table of n, a(n) for n=1..97.

Example

a(6) = 2 because 4*6 = 1 + 23 where (4*5+3)/3 = 23/3 > 6 and 4*6 = 5 + 19 where (4*4+3)/3 = 19/3 > 6.

Crossrefs

Cf. A002144, A006005, A280084.

Sequence in context: A093718 A278839 A348653 * A227752 A316771 A306269

Adjacent sequences: A278284 A278285 A278286 * A278288 A278289 A278290

Keyword

nonn

Author

Juri-Stepan Gerasimov, Dec 24 2016

Status

approved