OFFSET
1,1
COMMENTS
A subsequence of A008586.
LINKS
Ivan N. Ianakiev, Table of n, a(n) for n = 1..10000
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
KEYWORD
nonn,easy
AUTHOR
Ivan N. Ianakiev, Feb 16 2014
STATUS
approved