A353760 a(n) = 1 if A353749(n) > A353749(sigma(n)), otherwise 0. Here A353749(n) = phi(n)*A064989(n), and A064989 shifts the prime factorization one step towards lower primes.

0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0

Offset

1

Links

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

Index entries for characteristic functions

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to sigma(n)

Formula

a(n) = 1 if A353757(n) is negative, otherwise 0.

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));
A353760(n) = { my(s=sigma(n)); (A353749(s)<A353749(n)); };

Crossrefs

Characteristic function of A353758.

Cf. A353749, A353750, A353757, A353759.

Cf. also A353681, A353638, A353639.

Sequence in context: A353558 A353638 A324908 * A358770 A022925 A327211

Adjacent sequences: A353757 A353758 A353759 * A353761 A353762 A353763

Keyword

nonn

Author

Antti Karttunen, May 10 2022

Status

approved