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A375486
a(n) is the number of integers k between 0 and n such that n OR k is a prime number (where OR denotes the bitwise OR operator).
3
0, 0, 3, 4, 2, 6, 3, 8, 2, 4, 3, 8, 3, 8, 0, 0, 5, 12, 7, 16, 7, 14, 11, 24, 6, 12, 6, 12, 14, 30, 15, 32, 7, 14, 6, 12, 9, 20, 4, 8, 13, 28, 17, 36, 11, 22, 15, 32, 9, 18, 6, 12, 13, 28, 0, 0, 14, 28, 15, 32, 15, 32, 0, 0, 13, 26, 15, 32, 13, 26, 19, 40, 14
OFFSET
0,3
EXAMPLE
The first terms, alongside the corresponding k's, are:
n a(n) k's
-- ---- ------------------------
0 0 None
1 0 None
2 3 0, 1, 2
3 4 0, 1, 2, 3
4 2 1, 3
5 6 0, 1, 2, 3, 4, 5
6 3 1, 3, 5
7 8 0, 1, 2, 3, 4, 5, 6, 7
8 2 3, 5
9 4 2, 3, 4, 5
10 3 1, 3, 9
11 8 0, 1, 2, 3, 8, 9, 10, 11
12 3 1, 5, 9
13 8 0, 1, 4, 5, 8, 9, 12, 13
14 0 None
15 0 None
PROG
(PARI) a(n) = sum(k = 0, n, isprime(bitor(n, k)))
CROSSREFS
Cf. A375485 (XOR variant), A375487 (AND variant).
Sequence in context: A154570 A145961 A369557 * A082928 A139524 A247413
KEYWORD
nonn,base,easy
AUTHOR
Rémy Sigrist, Aug 17 2024
STATUS
approved