OFFSET
0,4
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..8192
EXAMPLE
The first terms, alongside the corresponding k's, are:
n a(n) k's
-- ---- ------------------
0 0 None
1 0 None
2 1 2
3 2 2, 3
4 0 None
5 1 5
6 2 2, 3
7 4 2, 3, 5, 7
8 0 None
9 0 None
10 4 2, 3, 6, 7
11 5 2, 3, 6, 7, 11
12 0 None
13 3 5, 7, 13
14 2 2, 3
15 6 2, 3, 5, 7, 11, 13
PROG
(PARI) a(n) = sum(k = 0, n, isprime(bitand(n, k)))
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Rémy Sigrist, Aug 17 2024
STATUS
approved