A089614 Number of primes between n^2 and (n+1/4)^2.

0, 1, 0, 1, 0, 1, 0, 1, 1, 2, 0, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 0, 2, 1, 2, 2, 2, 1, 2, 2, 3, 4, 2, 3, 4, 2, 4, 2, 5, 3, 2, 2, 2, 3, 3, 2, 2, 3, 2, 3, 5, 2, 3, 3, 2, 5, 4, 2, 4, 3, 4, 1, 3, 5, 3, 5, 6, 4, 5, 2, 3, 3, 6, 7, 6, 2, 5, 6, 2, 6, 4, 4, 3, 5, 3, 7, 3, 6, 4, 6, 2, 6, 6, 6, 5, 7, 7, 6, 4, 4, 4, 6, 7, 6

Offset

1,10

Links

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

Mathematica

Table[PrimePi[(n+1/4)^2]-PrimePi[n^2], {n, 110}] (* Harvey P. Dale, Jun 17 2018 *)

Prog

(PARI) pbetweensq2(n) = { for(x=1, n, c=0; for(y=floor(x)^2, (x+1/4)^2, if(isprime(y), c++) ); print1(c", ") ) }

Crossrefs

Sequence in context: A025862 A004540 A353945 * A064875 A216657 A328614

Adjacent sequences: A089611 A089612 A089613 * A089615 A089616 A089617

Keyword

easy,nonn

Author

Cino Hilliard, Dec 30 2003

Status

approved