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A373141
a(n) = 1 if A276085(n) is of the form 4m+2, otherwise 0, where A276085 is the primorial base log-function.
3
0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
1
FORMULA
a(n) = [A276085(n) == 2 (mod 4)], where [ ] is the Iverson bracket.
a(n) = A035263(n) - A369001(n).
PROG
(PARI)
A002110(n) = prod(i=1, n, prime(i));
A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
A373141(n) = (2==(A276085(n)%4));
CROSSREFS
Characteristic function of A373142.
Sequence in context: A285159 A073089 A373470 * A323158 A011657 A354896
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 26 2024
STATUS
approved