A373891 - OEIS

A373891

Number of primes less than prime(n) having the same difference between consecutive primes as prime(n).

0, 0, 1, 0, 2, 1, 3, 2, 0, 4, 1, 3, 5, 4, 2, 3, 6, 4, 5, 7, 5, 6, 6, 0, 7, 8, 8, 9, 9, 0, 10, 7, 10, 0, 11, 8, 9, 11, 10, 11, 12, 1, 13, 12, 14, 0, 1, 13, 15, 14, 12, 16, 2, 13, 14, 15, 17, 16, 15, 18, 3, 1, 16, 19, 17, 2, 17, 4, 20, 18, 18, 1, 19, 20, 19, 21, 2, 20, 3, 5

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OFFSET

1,5

LINKS

Table of n, a(n) for n=1..80.

Index entries for primes, gaps between

FORMULA

a(n) = |{j < n : A001223(j) = A001223(n)}|.

a(n) = A274121(n) - 1.

EXAMPLE

a(7) = 3 because A001223(7) = 2 and also A001223(2) = A001223(3) = A001223(5) = 2.

MATHEMATICA