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A219189 Parity of pi(5^n). 0
0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
0
COMMENTS
The parity of pi(n) is obtained without calculating pi(n), and much more quickly. See the paper below.
LINKS
Henri Lifchitz, Parity of pi(n)
EXAMPLE
a(4) = pi(5^4) mod 2 = 114 mod 2 = 0.
MATHEMATICA
Table[Mod[PrimePi[5^n], 2], {n, 10}]
CROSSREFS
Sequence in context: A189011 A189135 A369961 * A029691 A209229 A365089
KEYWORD
nonn
AUTHOR
Henri Lifchitz, Nov 14 2012
STATUS
approved

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Last modified March 19 07:49 EDT 2024. Contains 370958 sequences. (Running on oeis4.)