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A309333 The number of primes between two consecutive lucky primes, bounds excluded. 1
1, 1, 4, 0, 1, 4, 1, 0, 8, 4, 1, 5, 2, 0, 4, 7, 1, 3, 2, 2, 6, 1, 1, 5, 2, 6, 5, 3, 1, 1, 0, 1, 4, 6, 1, 4, 1, 4, 9, 5, 7, 0, 0, 2, 2, 5, 1, 3, 0, 8, 4, 1, 5, 2, 18, 0, 9, 3, 1, 1, 9, 2, 4, 5, 3, 2, 6, 5, 4, 9, 3, 4, 11, 1, 1, 3, 4, 20, 0, 8, 2, 4, 3, 3, 15, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..86.

EXAMPLE

a(1): Between the first two lucky primes (3, 7) is one prime (5).

a(3): Between 13 and 31 are 4 primes (17, 19, 23, 29).

PROG

(SageMath)

def count_primes_between(a, b):

  return len(prime_range(a+1, b))

[count_primes_between(A031157[i], A031157[i+1]) for i in range (len(A031157[0:20])-1)]

CROSSREFS

Cf. A031157, A309334, A176559.

Sequence in context: A172545 A124321 A232195 * A298924 A217476 A298622

Adjacent sequences:  A309330 A309331 A309332 * A309334 A309335 A309336

KEYWORD

nonn

AUTHOR

Hauke Löffler, Jul 24 2019

STATUS

approved

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Last modified July 13 17:54 EDT 2020. Contains 335689 sequences. (Running on oeis4.)