A353483 a(n) = 1 if n is a squarefree semiprime of the form (4t+3)*(4u+3), otherwise 0.

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

Offset

1

Links

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

Index entries for characteristic functions

Formula

a(n) = A353482(n) * A353492(n).

a(n) = A064911(n) * A353809(n), a(n) <= A353808(n). - Antti Karttunen, May 13 2022

Prog

(PARI)
A032742(n) = if(1==n, n, n/vecmin(factor(n)[, 1]));
A353492(n) = (3==(A032742(n)%4));
A353482(n) = ((2==bigomega(n)) && (2==omega(n)) && (1==(n%4)));
A353483(n) = (A353492(n)*A353482(n));

Crossrefs

Characteristic function of A016105, Blum integers.

Cf. A064911, A353481, A353482, A353492, A353808, A353809.

Sequence in context: A085982 A011735 A355816 * A353809 A353808 A353482

Adjacent sequences: A353480 A353481 A353482 * A353484 A353485 A353486

Keyword

nonn

Author

Antti Karttunen, Apr 22 2022

Status

approved