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A292598 a(n) is the number of odd primes in the sequence [n, floor(n/2), floor(n/4), ..., 1]. 4
0, 0, 1, 0, 1, 1, 2, 0, 0, 1, 2, 1, 2, 2, 2, 0, 1, 0, 1, 1, 1, 2, 3, 1, 1, 2, 2, 2, 3, 2, 3, 0, 0, 1, 1, 0, 1, 1, 1, 1, 2, 1, 2, 2, 2, 3, 4, 1, 1, 1, 1, 2, 3, 2, 2, 2, 2, 3, 4, 2, 3, 3, 3, 0, 0, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 2, 2, 3, 2, 2, 3, 3, 4, 4, 1, 2, 1, 1, 1, 2, 1, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..16384

FORMULA

a(1) = a(2) = 0; for n > 2, a(n) = A010051(n) + a(floor(n/2)).

a(n) = A000120(A292596(n)).

For all n >= 1, a(n) <= A078349(n).

PROG

(Scheme, with memoization-macro definec)

(definec (A292598 n) (if (<= n 2) 0 (+ (A010051 n) (A292598 (floor->exact (/ n 2))))))

CROSSREFS

Cf. A010051, A065091, A078349, A292596.

Sequence in context: A049321 A204425 A245187 * A079113 A144874 A303065

Adjacent sequences:  A292595 A292596 A292597 * A292599 A292600 A292601

KEYWORD

nonn

AUTHOR

Antti Karttunen, Sep 27 2017

STATUS

approved

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Last modified February 24 04:36 EST 2020. Contains 332197 sequences. (Running on oeis4.)