

A317419


a(n) = number of k with 1 <= k <= n1 such that a(k) AND a(nk) = 0 (where AND denotes the bitwise AND operator).


2



0, 1, 2, 2, 4, 4, 4, 6, 8, 8, 6, 6, 8, 8, 8, 10, 12, 12, 10, 14, 20, 14, 8, 10, 12, 12, 8, 8, 12, 14, 14, 10, 10, 12, 12, 8, 10, 14, 16, 12, 6, 10, 12, 14, 8, 8, 12, 14, 14, 14, 14, 10, 12, 12, 8, 12, 18, 16, 12, 8, 10, 14, 18, 14, 10, 18, 18, 16, 12, 14, 18
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OFFSET

1,3


COMMENTS

All terms are even except a(2) = 1.


LINKS



EXAMPLE

For n = 4:
 a(1) AND a(3) = 0 AND 2 = 0,
 a(2) AND a(2) = 1 AND 1 = 1 <> 0,
 a(3) AND a(1) = 2 AND 0 = 0,
 hence a(4) = 2.


PROG

(PARI) a = vector(71); for (n=1, #a, a[n] = sum(k=1, n1, bitand(a[k], a[nk])==0); print1 (a[n] ", "))


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



