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A065309
a(n) = prime(n) - prime(n - pi(n)).
5
0, 1, 3, 4, 8, 8, 12, 12, 12, 16, 18, 20, 24, 24, 24, 24, 30, 30, 36, 34, 32, 36, 40, 42, 44, 42, 42, 40, 42, 42, 56, 58, 58, 56, 60, 54, 60, 62, 64, 66, 72, 72, 82, 80, 70, 68, 80, 86, 88, 80, 82, 82, 84, 88, 90, 90, 90, 90, 96, 90, 92, 100, 110, 112, 102, 94, 108, 110, 118
OFFSET
1,3
LINKS
FORMULA
a(n) = A000040(n) - A000040(n - A000720(n)).
EXAMPLE
n=100, prime(100)=541, prime(100 - Pi(100)) = p(75), p(100) - p(75) = 541 - 379 = 162 = a(100).
MATHEMATICA
Table[Prime[n]-Prime[n-PrimePi[n]], {n, 70}] (* Harvey P. Dale, Apr 23 2016 *)
PROG
(PARI) a(n) = { prime(n) - prime(n - primepi(n)) } \\ Harry J. Smith, Oct 16 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 29 2001
STATUS
approved