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A102648

a(n) is the number of primes p between 0 and 99 such that 100*n+p is also prime.

9, 6, 15, 6, 5, 13, 5, 6, 12, 5, 6, 11, 6, 8, 11, 6, 7, 10, 6, 7, 10, 8, 6, 9, 4, 6, 11, 7, 4, 10, 3, 6, 13, 4, 8, 11, 5, 5, 11, 6, 4, 15, 3, 4, 10, 5, 6, 6, 7, 4, 10, 6, 3, 11, 5, 7, 7, 7, 3, 11, 5, 6, 14, 1, 4, 9, 5, 6, 10, 4, 3, 11, 2, 4, 12, 4, 7, 9, 3, 5, 8, 6, 5, 8, 5, 5, 11, 7, 4, 8, 4, 3

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OFFSET

1,1

COMMENTS

a(n) <= 20

LINKS

Table of n, a(n) for n=1..92.

EXAMPLE

a(2)=6 because 11,211,23,223,29,229,41,241,71,271,83,283 are primes.

MATHEMATICA

With[{prs=Prime[Range[25]]}, Table[Length[Select[prs, PrimeQ[100n+#]&]], {n, 100}]] (* Harvey P. Dale, Sep 03 2022 *)

PROG