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A353483
a(n) = 1 if n is a squarefree semiprime of the form (4t+3)*(4u+3), otherwise 0.
6
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
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.
Sequence in context: A085982 A011735 A355816 * A353809 A353808 A353482
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 22 2022
STATUS
approved