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A237990
Numbers m such that the numbers of primes, even positive integers and odd positive integers less than or equal to m are all even.
2
4, 8, 16, 20, 40, 44, 56, 64, 72, 80, 92, 96, 108, 116, 120, 124, 132, 136, 140, 144, 148, 152, 156, 164, 176, 184, 188, 196, 200, 204, 208, 224, 232, 240, 252, 256, 264, 268, 272
OFFSET
1,1
COMMENTS
A subsequence of A008586.
LINKS
FORMULA
a(n) == 0 (mod 4)
EXAMPLE
A tetrahedral die whose faces are marked with the numbers from 1 to 4 has an even number of sides marked with prime numbers, even integers and odd integers. Therefore, 4 is in the sequence.
MATHEMATICA
Select[Range[4, 1000, 4], EvenQ[PrimePi[#]] &] (* Paolo Xausa, Jun 24 2024 *)
CROSSREFS
Sequence in context: A181471 A272753 A272804 * A335792 A312807 A312808
KEYWORD
nonn,easy
AUTHOR
Ivan N. Ianakiev, Feb 16 2014
STATUS
approved