|
| |
|
|
A074210
|
|
Number of primes <= n is equal to the sum of primes from the smallest prime factor of n to the largest prime factor of n.
|
|
0
| |
|
|
1, 4, 12, 30, 272, 4717, 5402, 18487, 20115, 28372, 33998, 111040, 115170, 456975, 821586, 1874660, 4029676, 4060029, 59497900, 232668002, 313128068, 529436220
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| No more terms through 20000000. - Ryan Propper (rpropper(AT)stanford.edu), Jun 03 2006
|
|
|
EXAMPLE
| pi(272) = 58 and 272 = 2^4*17 and 2+3+5+7+11+13+17 = 58. ?
|
|
|
MATHEMATICA
| Do[l = First /@ FactorInteger[n]; m = Range[First[l], Last[l]]; If[Plus @@ Select[m, PrimeQ] == PrimePi[n], Print[n]], {n, 2*10^7}] - Ryan Propper (rpropper(AT)stanford.edu), Jun 03 2006
|
|
|
CROSSREFS
| Cf. A000720, A074036.
Sequence in context: A068055 A162740 A074252 * A005289 A037255 A027658
Adjacent sequences: A074207 A074208 A074209 * A074211 A074212 A074213
|
|
|
KEYWORD
| more,nonn
|
|
|
AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Sep 19 2002
|
|
|
EXTENSIONS
| More terms from Ryan Propper (rpropper(AT)stanford.edu), Jun 03 2006
a(19)-a(22) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Oct 12 2008
|
| |
|
|
