A353482 a(n) = 1 if n is a squarefree semiprime of the form 4k+1, 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, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 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, 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

For all n >= 1, a(n) <= A353477(n) <= A353480(n).

For all n >= 1, A353483(n) <= a(n) <= A353481(n).

Mathematica

Table[If[SquareFreeQ[n]&&PrimeOmega[n]==2&&Mod[n, 4]==1, 1, 0], {n, 150}] (* Harvey P. Dale, Oct 13 2024 *)

Prog

(PARI) A353482(n) = ((2==bigomega(n)) && (2==omega(n)) && (1==(n%4)));

Crossrefs

Characteristic function of A190299.

Cf. A353477, A353480, A353481, A353483.

Sequence in context: A353483 A353809 A353808 * A336355 A324731 A011734

Adjacent sequences: A353479 A353480 A353481 * A353483 A353484 A353485

Keyword

nonn

Author

Antti Karttunen, Apr 22 2022

Status

approved