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A078766 Number of primes less than n*phi(n). 0
0, 1, 3, 4, 8, 5, 13, 11, 16, 12, 29, 15, 36, 23, 30, 31, 58, 28, 68, 37, 54, 47, 96, 43, 95, 64, 92, 67, 141, 52, 158, 97, 120, 100, 146, 83, 217, 124, 158, 115, 259, 96, 279, 151, 180, 169, 326, 135, 310, 168, 258, 203, 402, 164, 327, 217, 309, 257, 480, 162, 511 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
FORMULA
a(n) = A000720(A002618(n)). - Michel Marcus, Sep 27 2013
EXAMPLE
phi(3)=2 and pi(2*3)=3, hence a(3)=3
PROG
(PARI) for (n=1, 100, ep=n*eulerphi(n); pc=0; forprime (p=2, ep, pc++); print1(pc", "))
(PARI) a(n) = primepi(n*eulerphi(n)); \\ Michel Marcus, Sep 27 2013
CROSSREFS
Sequence in context: A262951 A288091 A057926 * A336840 A253080 A050417
KEYWORD
nonn
AUTHOR
Jon Perry, Jan 09 2003
STATUS
approved

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Last modified March 29 04:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)