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A296021 Number of primes of the form 4*k+1 <= 4*n+1. 6
0, 1, 1, 2, 3, 3, 3, 4, 4, 5, 6, 6, 6, 7, 7, 8, 8, 8, 9, 9, 9, 9, 10, 10, 11, 12, 12, 13, 14, 14, 14, 14, 14, 14, 15, 15, 15, 16, 16, 17, 17, 17, 17, 18, 18, 19, 19, 19, 20, 21, 21, 21, 21, 21, 21, 21, 21, 22, 23, 23, 24, 24, 24, 24, 25, 25, 25, 26, 26, 27, 28, 28 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000

PROG

(Ruby)

require 'prime'

def A(k, n)

  ary = []

  cnt = 0

  k.step(4 * n + k, 4){|i|

    cnt += 1 if i.prime?

    ary << cnt

  }

  ary

end

p A(1, 100)

CROSSREFS

Cf. A016813, A091098, A295996, A296020.

Sequence in context: A305845 A120565 A244989 * A267097 A194198 A189674

Adjacent sequences:  A296018 A296019 A296020 * A296022 A296023 A296024

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Dec 02 2017

STATUS

approved

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Last modified September 21 15:27 EDT 2021. Contains 347598 sequences. (Running on oeis4.)