A177357 Number of positive squares <= prime(n) - 3.

0, 1, 2, 2, 3, 3, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 8, 8, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19

Offset

2,3

Links

Table of n, a(n) for n=2..79.

Formula

a(n) = A000196(A086801(n)). - R. J. Mathar, May 09 2010

Maple

A000196 := proc(n) floor(sqrt(n)) ; end proc:
A086801 := proc(n) ithprime(n)-3 ; end proc:
A177357 := proc(n) A000196(A086801(n)) ; end proc: seq(A177357(n), n=2..90) ; # R. J. Mathar, May 09 2010

Mathematica

Floor[Sqrt[Prime[Range[2, 80]]-3]] (* Harvey P. Dale, Dec 15 2018 *)

Crossrefs

Cf. A000006.

Sequence in context: A186704 A067434 A336348 * A320297 A165906 A165907

Adjacent sequences: A177354 A177355 A177356 * A177358 A177359 A177360

Keyword

nonn

Author

Giovanni Teofilatto, May 07 2010

Extensions

Edited by N. J. A. Sloane, May 08 2010

More terms from R. J. Mathar, May 09 2010

Reference redirected to a valid A-number by R. J. Mathar, May 09 2010

Status

approved