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A353482
a(n) = 1 if n is a squarefree semiprime of the form 4k+1, otherwise 0.
3
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
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.
Sequence in context: A353483 A353809 A353808 * A336355 A324731 A011734
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 22 2022
STATUS
approved