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A285699 a(1) = 1; for n > 1, a(n) = n - A079277(n). 6
1, 1, 2, 2, 4, 2, 6, 4, 6, 2, 10, 3, 12, 6, 6, 8, 16, 2, 18, 4, 12, 6, 22, 6, 20, 10, 18, 12, 28, 3, 30, 16, 6, 2, 10, 4, 36, 6, 12, 8, 40, 6, 42, 12, 18, 14, 46, 12, 42, 10, 24, 20, 52, 6, 30, 7, 30, 26, 58, 6, 60, 30, 14, 32, 40, 2, 66, 4, 42, 6, 70, 8, 72, 10, 30, 12, 28, 6, 78, 16, 54, 18, 82, 3, 60, 22, 6, 24, 88, 9, 42, 28, 12, 30, 70, 15, 96, 34, 18, 20 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The scatter plot has unusual "rays".

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

FORMULA

a(1) = 1; for n > 1, a(n) = n - A079277(n).

Other identities. For all n >= 1:

a(A285710(n)) = A000010(A285710(n)). [A285710 gives all such matches.]

MATHEMATICA

Table[n - If[n <= 2, n - 1, Module[{k = n - 2, e = Floor@ Log2@ n}, While[PowerMod[n, e, k] != 0, k--]; k]], {n, 100}] (* Michael De Vlieger, Apr 26 2017 *)

PROG

(Scheme) (define (A285699 n) (if (= 1 n) n (- n (A079277 n))))

(Python)

from sympy import divisors

from sympy.ntheory.factor_ import core

def a007947(n): return max(list(filter(lambda i: core(i) == i, divisors(n))))

def a079277(n):

    k=n - 1

    while True:

        if a007947(k*n) == a007947(n): return k

        else: k-=1

def a(n): return 1 if n<2 else n - a079277(n)

print [a(n) for n in xrange(1, 101)] # Indranil Ghosh, Apr 26 2017

CROSSREFS

Cf. A000010, A079277, A285710.

Sequence in context: A082175 A129292 A126606 * A278229 A233027 A262550

Adjacent sequences:  A285696 A285697 A285698 * A285700 A285701 A285702

KEYWORD

nonn,look

AUTHOR

Antti Karttunen, Apr 26 2017

STATUS

approved

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Last modified September 15 20:11 EDT 2019. Contains 327086 sequences. (Running on oeis4.)