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A089615 Number of primes between n^2 and (n+1/5)^2. 0
0, 0, 0, 1, 0, 1, 0, 1, 1, 2, 0, 0, 1, 2, 2, 1, 1, 1, 1, 1, 2, 2, 0, 1, 1, 2, 2, 1, 0, 2, 2, 2, 3, 1, 3, 4, 2, 4, 2, 4, 2, 1, 1, 2, 3, 2, 2, 2, 2, 1, 3, 4, 1, 2, 2, 1, 5, 2, 2, 4, 3, 4, 1, 2, 4, 3, 3, 5, 2, 3, 2, 3, 3, 5, 5, 4, 2, 4, 5, 2, 5, 2, 4, 3, 5, 2, 6, 3, 5, 4, 6, 1, 4, 6, 5, 4, 7, 6, 6, 4, 2, 3, 4, 4, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,10

LINKS

Table of n, a(n) for n=1..105.

MATHEMATICA

Table[PrimePi[(n+1/5)^2]-PrimePi[n^2], {n, 110}] (* Harvey P. Dale, Nov 10 2011 *)

PROG

(PARI) pbetweensq2(n) = { for(x=1, n, c=0; for(y=floor(x)^2, (x+1/5)^2, if(isprime(y), c++) ); print1(c", ") ) }

CROSSREFS

Sequence in context: A112020 A069160 A089616 * A089731 A097098 A123679

Adjacent sequences:  A089612 A089613 A089614 * A089616 A089617 A089618

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Dec 30 2003

STATUS

approved

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Last modified November 21 12:45 EST 2014. Contains 249778 sequences.