A057857 Number of residue classes modulo n-th primorial number which contain a prime.

1, 2, 4, 11, 52, 485, 5766, 92167, 1658888, 36495369, 1021870090, 30656102411, 1103619686412, 44144787456013, 1854081073152014, 85287729364992015, 4434961926979584016, 257227791764815872017, 15433667505888952320018

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Formula

a(n) = A005867(n)+n = A002110(n) - A057858(n).

Example

a(3) = 11 since 30 is the 3rd primorial number and 30k+m can be prime if m = 2, 3 or 5 (once each with k = 0) or m = 1, 7, 11, 13, 17, 19, 23 or 29 (each for an infinite number of values of k).

Crossrefs

Cf. A002110, A005867, A057858.

Sequence in context: A117157 A267013 A318532 * A352969 A091233 A173312

Adjacent sequences: A057854 A057855 A057856 * A057858 A057859 A057860

Keyword

nonn

Author

Henry Bottomley, Sep 08 2000

Status

approved