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A340203
Number of primes in A339399 among the values of A339399(k) for k = 1..n.
1
0, 0, 0, 1, 1, 2, 3, 4, 4, 4, 5, 6, 6, 7, 8, 8, 9, 10, 10, 10, 11, 12, 13, 13, 13, 14, 15, 15, 16, 17, 17, 17, 17, 17, 18, 19, 20, 20, 20, 21, 21, 21, 22, 22, 23, 24, 24, 24, 25, 26, 26, 26, 27, 27, 28, 28, 28, 29, 30, 30, 30, 31, 32, 32, 33, 33, 33, 33, 34, 35, 35, 35, 35
OFFSET
1,6
FORMULA
a(n) = Sum_{k=1..n} pi(c(k)) - pi(c(k)-1), where c = A339399.
EXAMPLE
a(14) = 7; There are 7 primes that are less than or equal to A339399(n). For example, the first 14 values of A339399(n) are 1, 1, 1, 2, 1, 3, 2, 2, 1, 4, 2, 3, 1 and 5 (7 of which are prime).
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Dec 31 2020
STATUS
approved