A353499 a(n) = 1 if n is a squarefree number for which the 2-adic valuation of phi(n) does not exceed the 2-adic valuation of n-1, otherwise 0.

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

Offset

1

Links

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

Index entries for characteristic functions

Formula

a(n) = A008966(n) * A353498(n).

Prog

(PARI) A353499(n) = ((n>1)&&issquarefree(n)&&(valuation(eulerphi(n), 2)<=valuation(n-1, 2)));

Crossrefs

Characteristic function of A339817.

Cf. A000010, A008966, A007814, A053574, A353498.

Sequence in context: A374130 A374466 A283991 * A359372 A327861 A131929

Adjacent sequences: A353496 A353497 A353498 * A353500 A353501 A353502

Keyword

nonn

Author

Antti Karttunen, Apr 22 2022

Status

approved