A353763 - OEIS

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A353763

a(n) = A353750(n) / gcd(A353749(n), A353750(n)).

4

1, 4, 1, 15, 1, 2, 2, 12, 11, 2, 4, 15, 5, 8, 1, 435, 3, 22, 4, 5, 2, 24, 8, 6, 29, 10, 1, 2, 12, 2, 8, 45, 4, 9, 4, 165, 17, 16, 5, 6, 3, 8, 10, 12, 11, 48, 16, 435, 204, 58, 3, 175, 36, 4, 4, 8, 4, 72, 48, 5, 29, 32, 11, 7119, 5, 24, 208, 45, 8, 8, 48, 66, 31, 34, 29, 20, 16, 10, 16, 145, 2695, 18, 120, 2, 3, 40

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Denominator of ratio A353749(n) / A353750(n).

LINKS

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

Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to sigma(n)

FORMULA

a(n) = A353750(n) / A353761(n) = A353750(n) / gcd(A353749(n), A353750(n)).

PROG

(PARI)

A064989(n) = { my(f=factor(n>>valuation(n, 2))); for(i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f); };

A353749(n) = (eulerphi(n)*A064989(n));

A353763(n) = { my(s=sigma(n), u=A353749(s)); (u / gcd(A353749(n), u)); };

CROSSREFS

Cf. A000010, A000203, A006872, A062401, A064989, A336549, A336550, A353757, A353761, A353762 (numerators), A353765 (positions of 1's).

Sequence in context: A145829 A016115 A164794 * A226478 A349124 A328235

Adjacent sequences: A353760 A353761 A353762 * A353764 A353765 A353766

KEYWORD

nonn,frac

AUTHOR

Antti Karttunen, May 10 2022

STATUS

approved