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A336546 a(n) = 1 if A051027(n) = Product_{p^e|n} A051027(p^e), and 0 otherwise. Here each p^e is the maximal prime power divisor of n, and A051027(n) = sigma(sigma(n)). 9
1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

a(n) = 1 => A336355(n) = 0.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions

Index entries for sequences related to sigma(n)

FORMULA

a(n) = [A336562(n) == 0].

For all n >= 1, a(n) <= A336556(n).

PROG

(PARI)

is_fun_mult_on_n(fun, n) = { my(f=factor(n)); prod(k=1, #f~, fun(f[k, 1]^f[k, 2]))==fun(n); };

A051027(n) = sigma(sigma(n));

A336546(n) = is_fun_mult_on_n(A051027, n);

CROSSREFS

Characteristic function of A336547 (gives positions of ones). Cf also A336548 (positions of zeros).

Cf. A051027, A065300, A324892, A336355, A336356, A336556, A336562.

Sequence in context: A334465 A054527 A137794 * A209929 A336556 A105586

Adjacent sequences:  A336543 A336544 A336545 * A336547 A336548 A336549

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jul 25 2020

STATUS

approved

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Last modified October 22 10:29 EDT 2021. Contains 348160 sequences. (Running on oeis4.)