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A373266
a(n) = 1 if A276085(n) is of the form 8m+4, otherwise 0, where A276085 is the primorial base log-function.
3
0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 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, 1, 1, 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, 1, 0, 1
OFFSET
1
FORMULA
a(n) = [A007814(A276085(n)) = 2], where [ ] is the Iverson bracket.
a(n) = A369001(n) - A373137(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)); };
A373266(n) = (4==(A276085(n)%8));
CROSSREFS
Characteristic function of A373267.
Sequence in context: A106197 A369048 A011722 * A276404 A277153 A323162
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 01 2024
STATUS
approved